1st International Workshop on Structural Health Monitoring for Railway System
1st International Workshop on Structural Health Monitoring for Railway System - DEStech
Local Damage Detection for Railroad Track NDE using Multi-channel MFL Sensor
In railway maintenance, the damage detection for local defects on railway at early stage is very important. Because, damages generated in a railway track have characteristics to grow fast and damages can cause mass disaster like derailment. In this study, a magnetic flux leakage (MFL) method which is suitable for the continuum ferromagnetic structure and verified by the previous studies was applied for the railroad inspection. To verify the feasibility of the proposed technique, a multi-channel MFL sensor head that minimized the lift-off was fabricated using Hall sensors and permanent magnets to adapt to the railroad. And a series of experimental studies including a field test were carried out. Test specimens with artificial defects on the surface were manufactured, and scanned by using the MFL sensor head to measure the magnetic flux density of the railroad specimen. Resolution of Measured magnetic flux signal was improved through the signal processing. Then MFL signals were analyzed for objective damage detection by comparing with threshold value. In the experimental result, MFL based method can detect successfully the local damages in high speed condition in field. Through the further research, it is expected that MFL based NDE technique can be applied effectively for detecting local damages of railway tracks by convergence of the suitable transportation equipment and IT technology.
Structures for Reducing the Loco Vibration
With the development of locomotive, the speed becomes higher, and the vibration happens frequently, it will harm many parts of the locomotive. In this article, we analyze the vibration reasons, and design new structures which can adjust the vibration for a kind of engine locomotive, even after the locomotive is assembled.
Research Development of Energy-absorption Structure for Railway Vehicles
Energy-absorption structure is the core component of railway vehicle crashworthiness. To provide a reference for the design of energy-absorbing structures, not only does this paper present the typical energy-absorbing structures including thin-walled, honeycomb and cutting structure, but it also discusses the influence of material properties, deformation modes and strain rate sensitivity on the collision characteristics of energy-absorbing structures. Further, the design patterns of energy-absorption structures for railway vehicles is summarized, and by using collision safety indicators, the design concepts of the bearing energy-absorption structures and special energy-absorption structures for railway vehicles are analyzed. The transient impact force acquisition system of the dynamic impact test on energy-absorption structure is introduced, and the comparative analysis is made between block type force panel wall and composite force panel wall. Finally, the main research direction of the railway vehicle energy-absorption structure is analyzed and predicted. Keywords: Railway Vehicle, Energy-absorption Structure, Dynamic Impact Test.
Study on the Strategy of Structure Health Monitoring on Chinese Railway Freight Car
The structure health monitoring system of railway freight car is operating under the railway transportation safety system and the railway freight car maintenance system. The structure health monitoring system of railway freight car, an integration system of hardware and software, provides the indicating information about faults and failures for the railway transportation safety system and the reference data for the railway freight car maintenance system. This paper presents a brief introduction about the current situation of structure health monitoring technology of Chinese railway freight car, proposes the strategy for structure health monitoring of railway freight car and states the key monitoring technologies that should be concerned in railway freight car development. Necessary suggestions to improve the railway infrastructure are proposed to let the structure monitoring technology of railway freight car function better.
LYU KEWEI, JUNFENG HAN, MAOSHENG HE and YUFENG CAO
Study on Fast Inspection Method for Car Body of Railway Vehicle Welded by Laser Overlapped Thin Steel Plates with Lamb Wave
A nondestructive testing method which can be used for finding lack of fusion defects in laser overlap welds every one of which joints two thin stainless steel plates is proposed based on reflection of ultrasonic Lamb wave. A B-scan testing system which implements the method is developed. Experimental testing on laser overlap welds of samples using the developed B-scan system is conducted. The results of experimental B-scan testing are compared with those of ultrasonic C-scan testing on the welds and observations on fracture surfaces of the welds. The agreements between the results of B-scan inspections and those of the other two kinds of inspections are satisfying. It is concluded that the developed B-scan technique is useable for inspections on laser overlap welds of rail vehicle bodies both in manufacture and periodical maintenance process.
XIAOHUI HAN, YE FU, GUANGKAI LI, GUANGYE JIA and GUIXI CAI
Research on Forecast and Alert Model for Journal Temperature of EMU
Changing pattern of Journal temperature of EMU shows the performance of shaft. Recent advances in deep learning technologies make it possible to learning features of Journal temperature. In this paper, we designed a special convolution-recursive neural network for pattern learning of Journal temperature, forecasting short-term variation and early warning of potential failures. We design multiple low-level convolutional neural network (CNN) learning Journal temperature changing mode which are then given as inputs to some Recursive neural network (RNN) in order to forecast Journal temperature. The recursive network also have fault data as inputs to learning probability of potential failures. Our main result is that this convolution-recursive neural network obtains state of the art performance parameters. On this basis, the network can be effective on short-term forecasting and potential failure warning.1
Electrical Simulation Analysis and Test Research of Railway Vehicles
In order to achieve the technique researches and innovations of railway vehicles, this article develop a set of simulator and analysis system of electrical design and test systemï¼Œ including software and hardware. The development and use of this system make it easy in designing and analyzing the principle diagrams. At the same time, it is much clearer for the designersâ€™ and testersâ€™ work through the visual action of electrical components in the circuit diagram. All the designation can be simulated before manufacture; the waste during manufacture can be reduced effectively. In additional, this system could also be used in commissioning, after sail service (ASS), repair and maintenance (R&M) of the vehicles, so the whole life cycle will be integration on the same electrical technology platform, the work time will also be shortened with the use of it.
Research and Application of Task Based Equipment in the Process of EMU Train Automatic Test
In order to solve the problems of data transmission in EMU train test, this paper presents a solution for the portable test equipment based on real time tasks, with this equipment, the test task management and the test process record can be combined together. By the technology of multi-thread process and speech telecommunication, the real time task information can be drive the equipment and trigger the test component to get the data and feedback, which can greatly improve the efficiency of EMU train test process and can help the work of test data maintain.
Application of Ultrasonic Inspection Technology to Measure the Air-tightness of Inter-city EMU
Based on the blockage ration when the inter-city EMU running in the tunnel, running pressure wave, air-tightness of cars, and analysis of airflow, the 140km/h grade inter-city EMU has higher tightness requirements to the normal mass transit vehicles. In case of air leakage during the air tightness test for inter-city EMU it is difficult to search the defect through traditional method such as hearing, touching and check by soap water. A testing method based on ultrasonic leakage inspection technology is proposed in this paper through this method the possible holes, crevice or poor sealing position in the cars can be located rapidly and correctly. The efficiency to measure the air leakage can be greatly improved. In the process method for ultrasonic leakage inspection is studied. The evaluation standard is defined. And the operation platform and management software for ultrasonic leakage inspection is established. The testing results for ultrasonic leakage inspection can be analyzed and output.
Application Method of HKS Intelligent Welding Monitoring System on CRH380 High Speed EMU Bogie
This paper according to the characteristics and functions of WeldQAS V5 HKS intelligent welding monitoring system. In this paper, the technology and method of combining intelligent monitoring system with welding robot to create a monitoring program is analyzed in detail. At the same time, the use of some functions of V5 WeldQAS system is described, and the monitoring technology is applied to the automatic welding technology of the side beam of high speed EMU bogie, It reflects the rail passenger car industry's most advanced intelligent control of welding quality results. Through the data of welding monitoring records, to achieve the welding products and parameters of traceability, not only effectively control the process parameters, reduce labor intensity of workers, but also improve the quality of welding significantly. It pointed out that the intelligent welding monitoring technology is an effective method to improve the degree of welding automation and ensure the quality of welding.
XIAOFENG ZHANG, GUOXING GAO and LIWEN MANG
The Monitoring of Long-Term Settlement of the Infrastructure and Vehicle-Caused Dynamic Response in Urban Rail Transit and Their Analysis
A comprehensive monitoring method and its system for infrastructure settlement and vehicle-caused dynamic response based on the Fiber Bragg Grating (FBG) technology was presented. The real-time, continuous, automatic, remote-control monitoring system was realized by combining automatic inspection, wireless data transmission and real-time data analysis. With this system, monitoring for different infrastructures settlement and vehicle-caused dynamic response such as shield tunnel, cover-cut tunnel, U-shape bridge with steep grade and sharp curve were carried on. Therefore, the relative settlement among different infrastructures along train running direction and the relationship between the settlement and the vehicle-caused dynamic response was recorded and analyzed. This method can satisfy the requirements of continuous monitoring infrastructures during long-term train operation and provide the reference for the infrastructure maintenance in urban rail transit.
Online Intelligent Identification of Resistance Spot Welding Quality Based on HMM for Stainless Steel Body of Metro Vehicle
A new online monitoring device of resistance spot welding quality parameter for stainless steel body of metro vehicle was introduced. For multiple pulse welding process of resistance spot welding of thick stainless steel, there are multiple pulse waveforms on the electrode displacement curve. Therefore, quality estimation of resistance spot welding can't be done using the traditional maximum electrode displacement method. In the article, the intelligent identification method based on Hidden Markov Model (HMM) was suggested for quality estimation of resistance spot welding. The electrode displacement curves under different welding current were classified into three groups, which are qualified welds, unqualified welds and splash welds. The splash welds can be monitored using the sudden drop of electrode displacement curve easily. Two HMMs were trained using Baum-Welch algorithm for qualified welds and unqualified welds. Then, the welding samples to be verified were identified using Forward-Backward algorithm. It was resulted that the 100% of welds were identified correctly using HMM method.
ZHONGCHENG JIANG, YING YANG, YEJUN MAO and ZHIMING WU
Effects of Ultrasonic Vibration on Weld Appearance and Microstructure of FSW of Aluminum Alloy
In the same welding parameters 6061-T6 aluminium alloy rolled sheets were friction stir welded with and without ultrasonic vibration (UV). Effects of UV on friction stir weld was illustrated by comparing the weld shape and corss-sectional macro- and microstructure. Ultrasonic Vibration made the microstructure change from TMAZ to WNZ more continuous than that of conventional FSW, which avoided stress concentration and sudden change in properties, and thus stabilized the appearance of the weld.
XIAOJUN DENG, HONGJU CUI, ZHIQIANG ZHANG, XIAOGUANG SUN, REN WANG, LICHUN MENG, TIEHAO ZHA
Structural Health Monitoring of Aluminum Alloy Carbody of High-speed EMU
This paper reveals that the real-time online structural health monitoring technology is effective to ensure the safe operation of high-speed EMUs given the structural features, service conditions and loading scenarios of aluminum alloy carbody. On this basis, this paper describes the state-of-the-art technology of active damage monitoring on the aluminum alloy carbody of high-speed EMUs, showing the current research achievements of CRRC Qingdao Sifang Co., Ltd. in applying SMART layer technology to carbody structural health monitoring, and prospecting the development goals of applying structural health monitoring technology on high-speed EMUs.
Design and Fabrication of MEMS Fluxgate Current Sensor with High Reliability and Low Cost for Train Health Monitoring
A great many sensors are utilized to monitor the running parameters in the train in order to maintain a healthy operating status. Among all the sensors, current sensors play an irreplaceable role in power electronic control system. At present, the current sensor based on fluxgate working principle is becoming more and more important in the field of railway transit measurement. However, traditional fluxgate current sensor shows some drawbacks, large volume and weight, great error in the assembly, high lost, etc. The Micro Electro Mechanical System (MEMS) technology focusing on electroplating process is widely used to fabricate the miniaturized fluxgate current sensor, which is not friendly to the environment and inefficient. Moreover, the production cost is high. In order to solve these problems above, the paper proposed a Through Silicon Vias (TSV) filling technology combined with MEMS technology to fabricate the micro fluxgate sensor, which can not only greatly reduce the volume and weight, but also can lower the producing cost and improve the performance. It can fully meet the requirements of current sensor for railway transit in miniaturization, integration, intelligence and high reliability.
DACHENG NI, FEI WANG, LIANGGUANG ZHENG and ZHUJIAN CHEN
Strain Monitoring of Fiber Reinforced Composites Based on Carbon Nanotube Thin Film Sensor
Carbon nanotube film has a microporous material property which make it can be integrated with composite material and does not change the original structural characteristic of composites. Moreover, its excellent piezoresistive properties can be used for real-time and online monitoring the strain of composite materials. In the present work, carbon nanotube thin film sensor had been prepared by the method of vacuum filtration, and then it has been attached to the surface of fiber reinforced composites for the strain monitoring of composite material. Experimental results of tensile tests show that the resistance rate of carbon nanotube film sensor will have a sudden change when the elastic limit is reached. And when the maximum stress is greater than the elastic limit, the residual resistance of sensor increased rapidly with the increase of the fatigue cycle. Nevertheless, the residual resistance change rate and sensing coefficient could stabilize after sever cycles. In conclusion, when the strain applied is not bigger than the elastic limit, carbon nanotube thin film sensor has a very good ability for monitoring the strain of composites synchronously and stably.
Process Monitoring of Fiber Reinforced Polymer Composites Using Carbon Nanotube Buckypaper Sensors
Buckypapers are free-standing porous mats of entangled CNT ropes cohesively bounded by van der waals interactions. For its high conductance and good compatibility with polymer composites, the resistance changes of BP and phase changes of polymer matrix have good correlation properties, So the BP sensors can be embedded into composite laminates for composite curing process monitoring. Experiment results show that the flow and gelation information of polymer matrix can be detected by BP sensors although the ply orientations of composite laminates are different. For the different ply orientations usually lead to different residual stress levels and deformation degree of composite structure, BP sensors show different resistance-temperature response during the cooling stage of composite cure cycle.
Feasibility of a Capacitive Strain Sensor for Fatigue Crack Detection of Steel Bridges
Cracks induced by fatigue have been a major issue for steel bridges. Currently, the most effective method to examine bridges for detecting fatigue crack activities is the inspection by human which is time consuming, labor intensive, cost inefficient and prone to error. As a replacement, measuring strain induced by cracks attracts many interests. However, traditional strain sensors such as metal foil strain gauges, are small and limited measurement range which make them not suitable for large cracks detection. Although some flexible materials developed to detect the strain, the parameter changed according to the strain is normally capacitance. This paper presents a capacitive strain sensor board transforming capacitance to analog voltage. Experimental tests show the linearity and real-time detection. Furthermore, the feasibility for using in fatigue crack detection by employing a strain-to-capacitance material is demonstrated.
A New Omni-directional Dual-mode Electromagnetic Acoustic Transducer for Ultrasonic Lamb Waves Inspection of Plate Structure
In recent investigations, omni-directional transducers have been developed for ultrasonic Lamb waves (ULW) imaging of defects in plate structure. This paper proposes an omni-directional dual-mode electromagnetic acoustic transducer (OD-EMAT) for generating and receiving pure single A0 mode and S0 mode ULW respectively in aluminum plate. The developed EMAT consists of a permanent magnet and a double layer coils with a circular meander coil in the upper and a spiral coil in the lower. The coils were integrated into the flexible printed circuit (FPC). Employing the developed EMAT, two ultrasonic Lamb modes can be realized under the condition of the same excitation source position. The performance of the developed EMAT was studied through the experiments conducted in an aluminum plate of 1mm thick. Firstly, it was verified that the A0 mode and S0 mode ULW could be effectively generated and received independently with the developed EMAT. Secondly, the omni-directivity of the developed EMAT was verified due to the even radiation pattern of 360 degree. Thirdly, the frequency response characteristic of the developed EMAT was investigated. The results show that the new OD-EMAT has good frequency response characteristics and validate the quantitative relationship between the center frequency and geometric parameter of the coils. Finally, three types of defects including bonded defect, through-hole defect and corrosion defect were detected. It is also shown that the measurements which were obtained from defects detection experimental appeared to have superior accuracy.
MUWEN XIE, YU GONG, YANAN HU, MEINING JI, CUNFU HE and BIN WU
Excitation and Reception of Shear Horizontal Waves by Using Face-shear Mode Piezoelectric Ceramics
The fundamental shear horizontal (SH0) wave in plate-like structures is extremely useful for non-destructive testing (NDT) and structural health monitoring (SHM) as it is non-dispersive. However, currently the SH0 wave is usually excited by electromagnetic acoustic transducers (EMAT) whose energy conversion efficiency is fairly low. The face-shear (d36) mode piezoelectrics is more promising for SH0 wave excitation but this mode can only exist in single crystals of specific point groups and cut directions. Theoretically the d36 coefficient vanishes in piezoelectric ceramics because of its transversally isotropic symmetry. In this work, we realize the face-shear (d36) mode in both PZT-4 and PZT-5H via ferroelastic domain engineering. The obtained d36 coefficients can be up to 274 pC/N in PZT-5H ceramics and 108 pC/N in PZT-4 ceramics. We then successfully excite SH0 wave in the aluminum plate using the fabricated face-shear d36 PZT-4 square patch and receive the wave using a face-shear d36 PMN-PT sensor. Although lamb waves are also excited simultaneously, the excited SH0 wave can be dominate over the Lamb waves (S0 and A0) from 160 kHz to 280 kHz. In order to excite pure SH0 wave, a newly defined face-shear d24 PZT wafer was then proposed. Experiments show that pure SH0 wave mode can be excited by the d24 mode PZT wafers. Moreover, the face-shear d24 PZT wafer can also receive the SH0 wave only and filter the Lamb waves over a wide frequency range (120 kHz to 230 kHz in this work). This work could greatly promote the applications of SH0 wave in NDT and SHM.
High-Performance Distributed Brillouin Optical Fiber Temperature/Strain Sensors and Their Applications in Structure Health Monitoring
In this paper, I will introduce the development of the high-performance distributed Brillouin optical fiber temperature/strain sensors under the cooperation between Harbin Institute of Technology (China) and University of Ottawa (Canada). The content includes long-rang distributed Brillouin optical fiber sensing with a 150km sensing range, high-spatial-resolution distributed Brillouin optical fiber sensing with a 2-cm resolution, and dynamic distributed Brillouin optical fiber sensing. The applications include the real-time monitoring of railway traffic and the full-scale strain distributions under load test of Haicang Bridge in Xiamen, China.
Intrinsic Self-Sensing Concrete for Smart Infrastructures
Intrinsic self-sensing concrete (ISSC) refers to a structural material that can monitor itself without the need of embedded, attached or remote sensors. By measuring electrical resistance of the ISSC, the stress, strain, crack and damage can be in situ monitored. Compared with conventional structural materials which require additional sensors for monitoring or detection, the ISSC is advantageous in its high sensitivity, good mechanical property, natural compatibility, identical lifespan with concrete and easy installation and maintenance. The ISSC can be used for structural health monitoring, traffic detection and border/military security. In this paper, the ISSC with single filler (including microscale fillers and nanoscale fillers) and hybrid fillers are introduced.
SUFEN DONG, SIQI DING, SHENGWEI SUN and BAOGUO HAN
Longitudinal Additional Force Testing Method For Continuous Welded Rail With Hetero-Cladding FBG Strain Sensor
A new method has been proposed to accurately determine longitudinal additional force in continuous welded rail (CWR) by two Fiber Bragg Grating sensors with a little difference center wavelength but hetero-cladding diameters. As shown in the test results, the linearity between relative wavelength difference and longitudinal additional force is greater than 0.9999. Moreover, the relative wavelength difference is not affected by the temperature changing with the hetero-cladding FBG. Compared to theoretical results, the accumulated error is controlled within 2.2Ã¯Â¼â€¦ in harsh environment.
Automated Health Monitoring of Rail Cars and Railroad Bridges Using Embedded Sensors
Current maintenance operations and integrity checks on a wide array of structures require personnel entry into normally-inaccessible or hazardous areas to perform necessary nondestructive inspections. To gain access for these inspections, structure must be removed, sealant must be removed, disassembly processes must be completed, or personnel must be transported to remote locations. The use of in-situ sensors, coupled with remote interrogation, can be employed to overcome a myriad of inspection impediments stemming from accessibility limitations, complex geometries, the location and depth of hidden damage, and the isolated location of the structure. Furthermore, prevention of unexpected flaw growth and structural failure could be improved if on-board health monitoring systems were used to more regularly assess structural integrity. Reliable Structural Health Monitoring (SHM) systems can automatically process data, assess structural condition, and signal the need for specific maintenance actions. A research program has been completed to develop and validate Comparative Vacuum Monitoring (CVM) Sensors for surface crack detection. The test specimens included those designed to simulate crack origination sites on aircraft and bridge structures. The test matrix studied the affects of surface coating, skin thickness, and material type on the performance of the CVM sensors. Statistical methods using one-sided tolerance intervals were employed to derive Probability of Detection (POD) levels for each of the test scenarios. The result is a series of flaw detection curves that can be used to propose CVM sensors for crack detection. Complimentary, multi-year field tests were also conducted to study the deployment and long-term operation of CVM sensors on aircraft and bridges. This paper presents the quantitative crack detection capabilities of the CVM sensor, its performance in actual operating environments, and the prospects for structural health monitoring applications on a wide array of civil structures.
Advanced Transducers for Remote Sensing and Structural Health Monitoring
This paper reports on the design and testing of a novel class of ultrasonic/guided wave transducers for structural health monitoring. The transducers are particularly suited for harsh environments and remote monitoring of complex structural components. The design methodology takes advantage of the Fourier representation of the transducer and allows for smart patterning of the transducer inner shape, resulting in enhanced performance and reduced complexity of the devices. The design enables continuous beam steering and directional sensing which are achieved through proper selection of the excitation frequency (actuation mode), or through the detection of the dominant harmonic components in recorded signals (sensing mode). The design consists in a spiral geometry in the wavenumber domain, and thus is denoted as Wavenumber-Spiral Frequency Steerable Transducer (WS-FSAT). WS-FSATs are examples of a next generation of acoustic transducers that can significantly improve the practicality of guided-wave based sensors for structural health monitoring through embedded sensors in hard-to-reach areas.
Application of IEEE 802.15.4 Based Wireless Sensor Network on Low Power Consumption Train
The existing train basically adopts wired network such as CAN, MVB and WTB networks (conforming to the IEC 61375 protocol) connected to the sensor, actuator and controller. These wired sensor networks have the advantage of mature technology and reliable work but they are also limited by cost and volume of the sensor. Besides, monitoring nodes are difficult to arrange and wire, and the maintenance cost is too high to expand network monitoring. With the rapid development of big data and artificial intelligence nowadays, these technologies become a hot topic in the field of research on intelligent train while demanding for backup of large amounts of perception data. The current wired sensor network, however, is difficult to meet the increasing demand of train intelligence for the perception system. The wireless sensor network technology adopts distributed network protocol which supports self-organization of the network and reconfigures the network automatically in case of partial nodes failure. Without limitation of wiring, the networking process becomes rather convenient. The rapid development of MEMS technology makes miniaturization of sensor nodes possible, which can be easily embedded in every part of the car body structure. On a basis of IEEE 802.15.4 technology, this paper introduced the key technology and application field of train wireless sensor network with low power consumption, such as wireless communication technology with low power consumption and short distance, sensor technology with low power consumption and technology of energy collection and storage. The focus is on the issues such as reliability and real time of the wireless sensor network protocol which is based on IEEE 802.15.4 technology in case of train environment. Related research directions are also pointed out.
Troubleshooting of a Sheathed Thermocouple Type of Temperature Sensor
A kind of temperature sensor designed with sheathed thermocouple was introduced. A suitable procedure for troubleshooting was worked out for the sensor fault case occurred during the process of monitoring the oil temperature of a gas turbine. Depending on the primary analysis of trouble phenomenon, trouble principle was analyzed. Detection means like electrical measurement, flaw inspection, local disassembly, etc. were utilized comprehensively to locate the exact fault cause. The sensor coupling technique for connecting the sheathed thermocouple tail and the electric connector was optimized and improved. In order to avoid hidden trouble resulted from production manufacturing segment and improve the fault tolerance in product assembly, three different optimization schemes were proposed and compared with each other. By an overall consideration of sensor safety, reliability and maintainability, the best solution has been adopted to solve the sensor fault. Experience was accumulated for design optimization of the same type of sensor. Keywords: Sheathed Thermocouple, Temperature Sensor, Troubleshooting, Technique Optimization, Maintainability
QI SUN, ZHONGKUI LIU, XIAOLIANG WANG and YUEFEI CHEN
Integrated Structural Health Monitoring Technology
Similar with civil aircraft, Structural Health Monitoring (SHM) based on sensor network on railway systems may bring a great impact on structure design, improve the safety and reliability, reduce maintenance and operation cost. By implementing a built-in sensor network on the railway structure, crucial information regarding the condition, damage state, and service environment of the structure can be obtained. This paper first introduces the general perspectives of commercial aircraft company on SHM as a reference of the railway SHM, and addresses the basic design principles of an SHM system for a large civil aircraft, including the integrated system architecture and the composition of various subsystems. Some key features of an implementable SHM system are then discussed, including sensor survivability, integration of large sensor network with the aircraft structure, damage quantification and environmental compensation, airworthiness compliance. Finally, a demonstration of integrated passive and active SHM based on SMART Layer technology is carried out on a large fuselage panel and a wing structure for real-time impact monitoring and damage detection.
Key Parameters Analysis of Urban Rail Transit Sensor Networks
Traffic sensor network may choose a different perception model and structure based on fixed facilities, mobile equipment and group behaviour. A unified architecture will be used to combine all the sensory information fusion. So it is a multiple reconfigurable sensing system. Based on the concepts and principles of traffic sensor, this paper made a detailed study of urban traffic sensor network functions, and the realization of a universal architecture of these required functions, further discussion has also been made on the key performance indicators of transportation intelligence sensory system, which laid the foundation for future study.
HAICHUAN TANG, HAICHUAN TANG and XIAOHUI ZHANG
Applications of Distributed Fibre Optics Sensing to Railway Industry
Distributed Fibre Optics sensing was known for the last three decades, but it has been only recently, during the last 15 years, after the discovery of high spatial resolution sensing, when different industrial applications have been demonstrated in aeronautics, civil engineering, and also for transport and railway applications. Within this technology, a plain optical fibre is sensitive at each point of its length to strain/temperature changes, and consequently, it will detect a crack crossing the path of the optical fiber, as a very high spot for strain concentration. After introducing the physical principles and different approaches, their performances will be compared, and examples of real case applications will be shown. Most of the existing researches have addressed the measurement of strains at the rail track, to monitor the moving loads, and also the movements of the supporting ground, particularly the occurrence of sinkholes. Less common are those applications at which the optical fibre and the interrogation system are mounted on the carriage itself, to determine its structural integrity. Lecture concludes with ongoing developments in Europe, particularly for high speed trains.
Condition Monitoring, Detector Data and Information Architecture in North America
Condition and performance monitoring technology has expanded its reach into daily usage by railways in North America and the data has been weaved into the fabric of maintenance by using big data architecture. The technology uses wayside or trackside detection systems that monitor the health of equipment components as each train passes. The systems measure component performance or identify component condition such as bearings, wheels, brakes, and trucks (bogies). This paper provides recent advances in detectors, the data management systems, and the data architecture that allow timely maintenance policies, which are moving from reactive to preventive and predictive.
In-Situ Monitoring of Integrity of Train Bolster Through Guided Wave Structural Health Monitoring (SHM) System
A study was performed by Acellent Technologies in collaboration with CRRC to develop an on-board health management system for monitoring in real-time the integrity of structural components due to cyclic fatigue loads for high-speed train systems. In this study, the bolster in high speed trains was the primary focus of the investigation. The bolster components located under the train body are typically welded together and subjected to various types of loadings (compressive, tensile, shear etc.) at different locations. Hence, it makes the bolster structures more susceptible to fatigue cracks and debond failures. An AcellentÃ¢â‚¬â„¢s guided wave-based SHM system was selected for monitoring crack- and debond-prone damage areas in bolster structures. Several test cases including wave propagation, simulated damage, and real damage cuts were introduced on a real bolster structure to evaluate the sensitivity of the proposed SHM system.
SHAOQING LIU, PENG LIN, VISNUVARDHAN JANAPATI, SUSHEEL KYMAR YADAV, FRANKLIN LI, HOWARD CH
Sensor Network Design Technique for Monitoring Railroad Structures
Components of high speed trains such as bolsters and bogie are subjected to continuous dynamic loads under varying environmental and operational conditions. Scheduled maintenance of these components at regular intervals is not feasible as these inspections are costly, burdensome, and increase structural downtime. Moreover these conventional inspections require dis-assembly of different components of the train structure. Oftentimes these dis-assemble and re-assemble operations leads to new damage initiation if these operations are not followed correctly. Structural Heath Monitoring (SHM) technologies are ideal solutions to monitor this kind of critical structure. Guided Wave-based Structural Health Monitoring (SHM) techniques are currently widely used in aerospace and energy industries to monitor structural damages such as fatigue crack, delamination, debond, and corrosion etc. The damage detection sensitivity of any SHM technique highly depends on the sensor network design. This paper presents model-based quantification technique to design and verify the performance of the sensor network. In a joint program between the CRRC and Acellent Technologies, sensor network design techniques were demonstrated and validated through case studies on high speed train bolsters.
FRANKLIN LI, VISHNU JANAPATI, HOWARD CHUNG, SUSHEEL KUMAR YADAV and CAS CHEUNG
Monitoring System of Bottom Door Under Locking Status
Due to coal hopper wagon over-limit when bottom door opened, after opening the doors of loaded wagon must empty coal in the wagon before closing bottom door, lines occupy a long time, so customers and transportation department take coal hopper wagon bottom door locking condition very seriously, and eager to install connecting rod locking condition monitoring system, in order to monitor bottom doors locking condition effectively. For this purpose, we develop bottom door locking condition monitoring system which can inspect, alarm, monitor and record bottom door locking condition. When close bottom door, the system will gives alarm signal to alert operating personnel if bottom door connecting rod not locked in place; train inspection personnel also can use handheld inspection equipment to inspect marshaling, in order to confirm the bottom door locking condition is good. Most of coal hopper cars adopt 4 bottom doors on both sides of top lock type opening/closing mechanism switch in China, three-level lockup devices are set, and Level-I lockup is top locking mechanism which is installed between bottom door pin and the long/short push rods. The arc surface of lock body bearing the force of bottom door pin is a circular arc with the rotary center of the lock body as the center, the bottom door pressure stressing on the lock body is through the rotation center of the lock body, so the lock body and bottom door pin are in balanced status in any point of the pressure of bottom door pin on the arc surface, the lock body will not rotate due to the increase or decrease of acting force of bottom door pin; lockup function is also very reliable even the scattered goods are compacted during long distance of transportation. To prevent lock body from opening automatically due to the vibration of empty vehicle during the running, an eccentric connecting rod is designed between the upper and the lower drive shafts of two level rotation, with the eccentricity of 15+2mm, and such connecting rod can only be opened after turning over dead point so as to lock the lower drive shaft and the lock body in designated rotation position to form into the Level-II lockup device.
WENSHENG LIU, HERA WIDYASTUTI and WING KONG CHIU
CNT-based Multifunctional Concrete for High Speed Railway
This study is to investigate the feasibility of CNT (Carbon Nano Tube) increasing the thermal conductivity and strength of cementitious composites in order to build and apply multi-functional concrete to a high speed railway. The test parameters include CNT concentration, input voltage, and curing age. Specimens are prepared by varying concentrations of CNT by the weight of cement. Two different manufacturing processes are considered for CNT cementitious composite specimens. The first method utilizes CNT-coated sand while the other makes use of aqueous CNT solution. An electric current is applied to the specimen in order to generate heat and the elevated temperature is measured using thermocouples. The measured thermal conductivity from CNT cementitious composites are compared to that of ordinary Portland cement (OPC) specimens. Furthermore, all specimens are loaded to determine their compressive strengths. Both strength and temperature results are presented.
Signal Acquisition and Analysis for Rail Steel Flaw Based Laser Ultrasonic Method
Railway steel flaw inspection has great significance for train safety operation. This paper describes signal acquisition and analysis for rail steel flaw inspection with laser ultrasonic method. With acquisition system DAQ600 designed for rail steel flaw detecting, the rail steel flaw signal can be acquired and measured efficiently, which provides a good solution for railway life evaluation. After amplified and sampled by DAQ600, the ultrasonic signals of rail steel flaw were converted into 16bit data. Through filtered and adopted multiple average, the ultrasonic data can be displayed on the terminal computer in real time. And the flaw position can be located accurately with the EMAT (electromagnetic acoustic transducer) probe.
ZHENZHEN ZHANG, QIWU WANG, RUI GUO and JIANGFENG SONG
Information Fusion about Rolling Bearing Fault Diagnosis Based on SVM and D-S Evidence Theory
Multi-sensor information fusion, when applied to fault diagnosis, the time-space scope, and the quantity of information are expanded compared to what could be acquired by a single sensor, so the diagnostic object can be described more comprehensively. The method of support vector machine (SVM) and D-S theory were presented in this paper to solve the problems about low detection accuracy, difficulty in extracting sensitive characteristics and unstable diagnosis system of single-sensor in rolling bearing fault diagnosis. Wavelet de-nosing technique was used for removing the signal noises. SVM was used to make pattern recognition of the bearing vibration signal, and then fusion process was made according to the D-S evidence theory, so as to realize recognition of bearing fault. The results indicated that the data fusion method improved the performance of the intelligent approach in rolling bearing fault detection significantly. Moreover, the results showed that this method can efficiently improve the accuracy of fault diagnosis.
Weak Bearing Fault Diagnosis with Optimized Morlet Wavelet and Kurtosis
To achieve the early fault diagnosis for rolling bearings, this paper proposes a new transient fault detection approach by the use of optimized Morlet wavelet transform, kurtosis index and soft-thresholding. Firstly, a fast optimization algorithm based on the Shannon entropy is developed to obtain the optimized Morlet wavelet parameter. Compared to the existing Morlet wavelet parameter optimization algorithm, this algorithm has lower computation complexity. After performing the optimized Morlet wavelet transform on the analyzed signal, the kurtosis index is used to select the characteristic scales and obtain the corresponding wavelet coefficients. From the time-frequency distribution of the periodic impulsive signal, it can be found that the transient signal should be reconstructed by the wavelet coefficients at several characteristic scales rather than the wavelet coefficients at just one characteristic scale, so as to improve the accuracy of transient detection. Due to the noise influence on the characteristic wavelet coefficients, the adaptive soft-thresholding method is applied to denoise these coefficients. With the denoised wavelet coefficients, the transient signal can be reconstructed. The proposed method has been applied to analyze a simulated signal with a weak impulse, and diagnose a rolling bearing fault. The superiority of the method over the fast kurtogram method has been verified by the results of simulation analysis and real experiments. It can be concluded that the proposed method is extremely suitable for extracting the periodic impulsive feature from the strong background noise.
Delamination Detection of Composite Plate Base on Wavelet Correlation Damage Index of Time Reversal Guided Wave
The self-focusing ability of Time Reversal Guided Wave (TRGW) is studied in the damage detection of composite laminates. The finite element modeling of delamination is developed to investigate the potential of TRGW as non-based damage detection system. The similarity index and the damage index are used to evaluate the self-focusing ability at different exciting frequencies, based on which the optimal excitation frequency is determined. The wavelet correlation damage index is proposed based on the correlation between the TRWG wavelet coefficients of response signal and baseline data. By conducting probability analysis of wavelet correlation damage index in the composite plate with delamination, the damage area is reconstructed. Simulation experiment shows that using the proposed index can accurately image the delamination damage with high-resolution, which would provide data support for further imaging research based on time reverse theory.
Vibration Failure Analysis and Vibration Reduction Scheme for Traction Converter Control Cabinet of Locomotive
For the phenomenon of high failure rate of traction converter control cabinet, on-site vibration test and analysis were carried out, it proved that the vibration of control cabinet installed base was too large was the main cause of the high failure rate. On this basis, the vibration reduction solution of control cabinet was proposed; simulation analysis and loading test verification were carried out. The simulation results agree well with the loading test results, the vibration reduction solution of control cabinet has good vibration isolation effect and engineering practical value, so that it is of high popularization value.
JIE DING, XIAOBIN ZANG, HAITAO LIU, ZHENGLIN CHENG and SHAOLONG XU
Use of WLI and FBG Technique to Monitor the Residual Strains of Concrete Caused by Freeze-Thaw Damage
In this study, Fiber Bragg grating (FBG) and white light interferometer (WLI) sensing technique are introduced and used to monitor the concrete residual strain caused by freeze-thaw damage. Concrete specimens wrapped with optical fiber are subjected to multiply cycles of freezing and thawing. Expansion strain of concrete caused by freeze-thaw damage in real-time. The test results show that, the residual strain sensitively measured by optical fiber sensors was basically fitted with the phenomenon that the residual strain increased along with the number of freezeâ€“thaw cycles, and indicate that two fiber sensing techniques were able to monitor the concrete freezeâ€“thaw damage. Meanwhile, comparing the two techniques from four aspects, WLI was more suitable for residual strain monitoring in concrete freezeâ€“thaw damage.
Fault Analysis and Detection Method of the EMU Traction Motor
A study proposed in this paper is based on EMU traction motor failure. The incipient periodic fault characteristic signals of rotor bars breaking are very weak, and the useful signals submerged in the noise are difficult to be detected. The fault detection method was combination of Duffing oscillator and wavelet packet energy analysis. The system characters were analyzed and testified by the simulation and the experiment.
Applications of Laser-Based Ultrasonic Testing Technique on Nondestructive Testing and Structure Health Monitoring
This paper introduces the laser-based ultrasonic technique and its application in the fields of nondestructive testing (NDT) and structure health monitoring. A Q-switched Nd:YAG laser with wavelength of 1064nm and pulse duration of 10 ns was used to generate ultrasound including bulk wave and Rayleigh wave. For the various purposes in practical engineering, electromagnetic acoustic transducer (EMAT), laser interferometer and fiber Bragg grating (FBG) sensing system were employed as employed as discrete sensing elements to detect the ultrasonic generated by pulsed laser. These detector systems had their own advantage and range of frequency responses which decide to their application fields. Conventional piezoelectric transducer (PZT) was also used in the experiments to compare with the laser-ultrasonic testing results.
JIHUA SUN, ZHENZHEN ZHANG, JIANGFENG SONG, JIAN MA, SHUAI LIU and YINIAN ZHU
Some FBG-Based Damage Identification Techniques Applicable to Structural Health Monitoring for High-Speed Trains
Fiber Bragg gratings (FBGs) have some advantages such as lightweight, small in size, immune to electro-magnetic interference, highly sensitive, quasi- or truly-distributed sensing of strain or temperature, etc. Therefore, FBGs have been promising sensors for structural health monitoring (SHM). In this paper, some typical damage identification techniques based on FBGs are presented, which were developed in our work in the last decade. They are damage identifications in modal strain space and in phase space, respectively, and the damage reconstruction (or damage imaging). The theories as well as the measurement techniques using FBGs for these approaches are outlined, along with several numerical and experimental validations. Finally, their potential applications in the SHM for high-speed trains are discussed.
GUOWEI YANG, CHANGBEN WEI, SHIYUAN CHEN, ZHONGHUA JIANG and MING WU
Research and Experiment on the Vehicle and Guideway Coupling Relationship of High-speed Maglev Train in the Curve Negotiation
When the high-speed maglev train is moving, with the increase of the vehicle speed, vehicle and guideway coupling vibration becoming a great impact on the safety and comfort. Since there is only Shanghai magnetic suspension demonstration operation line in commercially operation in the world at present, the research on the vehicle and guideway coupling of high speed maglev system, especially in the curve negotiation is insufficient. Based on the vehicle acceleration data of the elastic suspension frame and the guideway which is acquired from the Shanghai high-speed maglev test line, through analyzing the behavior and structure performance of train body and the guideway during moving, the research provides experimental basis for further work on the vehicle and guideway coupling relationship of high speed maglev train in the curve negotiation.
Diagnosis Technology Investigation on High-Speed EMU Axle-box Bearings with Local Damages
The EMU axle bearingsÃ¢â‚¬â„¢ damage can cause increasing of both the vibration and temperature of the shaft. Temperature monitoring is used for fault monitoring, but it often leads to false message. So the EMU axle bearing fault diagnosis based on vibration signals have important applications. In this paper, diagnosis investigation based on a bearing experiment rig is introduced. The tests indicate that because the fault locations are not fixed but varying with the rotating inner race and rolling element, all orders of fault characteristic frequencies are very complex due to the frequency modulation when the local damage happens on the inner race or the rolling element. It is hard to detect the local faults by the conventional FFT processing. So the SR spectra are adopted, based on the stochastic resonance method, to effectively extract the fault characteristic frequencies. Based on the above researches, a monitoring and diagnosis system was developed, which can be used for early warning and judgment for the axle bearing fault of the bullet trains.
BINGBING HAN, TAO GUO, CHAO AN, MINGGAO LI and QIAN DING
Vibration based Static Monitoring of Rolling Element Bearing in High Speed Trains
Vibration based method has been widely used as a powerful tool to assist condition monitoring of rotating machines. In order to eliminate the indeterminacy induced by conventional manual detection of rolling element bearing in high speed trains, a vibration based static monitoring process has been proposed. Kurtogram algorithm is firstly used to remove the noise in the original vibration signal of rolling element bearings. Subsequently, envelope analysis is applied to extract characteristic vibration features of roller bearings. The practical test has proved the effectiveness of the proposed semi-automatic method for condition monitoring of axle box bearing in high speed trains.
GUANJI XU, ZHIQIANG ZHANG, HAITAO LI and NING LI
Extracting Defective Features from Noisy Guided-waves Signals that are Reflected by the Defects Located Inside the Concrete-covered Section of a Pipe
Pipes are widely used in infrastructures for delivering water, chemical and gas. These pipes are partially either covered by concrete or buried in ground. Due to humidity in the atmosphere, they are prone to developing corrosion. However, the early detection of corrosion on the sections that are covered by concrete or soils is nearly impossible. If severe corrosion is allowed to continually occur, it may cause pipe rapture. Consequently, train service will be interrupted and unexpected accidents may occur. To facilitate early detection of corrosion occurring in these partially covered pipes, we investigated the capability of guided waves (GWs) in detecting defects through analyzing the received GWsÃ¢â‚¬â„¢ signals that were reflected by various defects. Although GW had found to be effective in locating defects and estimating the extent of corrosion, a proper signal processing tool must be used to extract defects related features from blurred signals due to noise and undesired GWs mode conversion. This paper reports the use of GWs-based method to detect the defects and Continuous Wavelet Transform (CWT) to recover vital defect related features from corrupted GWs signals. To ensure the relevant GW signals can be observed, the signal of emitted tone-burst signal was used as the mother wavelet of the CWT rather than the conventional Morlet wavelet. With the help of such mother wavelet, the CWT can effectively minimize the noise and irrelevant signals. Real in-service pipes were used to verify the effectiveness of such CWT. After its application, the entry and the exit sections of the pipes that are covered by concrete wall can be identified. Most importantly, the defects located within the concrete covered section can also be revealed. The on-site tests prove that the GWs inspection method and the CWT that is using the tone-burst signal as the mother wavelet of CWT can efficiently detect corroded areas even they are covered by concrete wall.
Design of a Structural Health Monitoring System Based-On PZTs and Lamb Waves
The structural health monitoring technique based-on PZT and Lamb waves and its system were researched for the urgent demand and application immaturity of damage detection in railway system. It firstly discussed the research status of structural health monitoring methods and system, and then it proposed an identification algorithm of structural damage based on damage index. Furthermore, it designed the active structural health monitoring system, and then carried out the experiment and verification of the system on helicopter tail boom. The experimental results have shown that the designed monitoring system could be reliable, stable, and sensitive to the damage with broad application prospect in critical components of high-speed transport.
HONGZHENG FANG, JIAN LIU, HUI SHI and JIANBING SHAN
Study on Assessment of Ballast Condition Using Tracking Loading Vehicle and Ground Penetrating Radar
Investigation and assessment of track components can improve the safety of running vehicles, but there are no mature methods of ballast condition testing. In combination of testing and correlation analysis, testing and assessment of ballast condition based on TLV (Tracking Loading Vehicle) and GPR (Ground Penetrating Radar) is introduced in this paper. Investigation was done on Jing-Guang line between XinYang and HengDian using TLV and GPR, and correlation between track stiffness and track irregularity was analyzed. The result shows: track stiffness is significantly correlated with track vertical profile, the average value and standard deviation track vertical profile is relatively smaller when track stiffness is between 60kN/mm and 160kN/mm. For different section of ballast cleaning date, the average value of track stiffness becomes bigger with the tonnage increasing, and the percentage of higher and lower track stiffness increases.
The Research on Life Prediction Method of Safety Relay
In order to improve the reliability and utilization of the safety relay, in this paper, failure mechanism and life prediction method of the railway signal relay were deeply studied. A variety of multivariate statistical analysis methods such as PCA and Mahalanobis distance are adopted to do data fusion and feature extraction of relay contact resistance, closing time, release time, super-path time, arc time and bounce time degradation parameters in the process of life test. Thus, parameters of the safety relay test are extracted and all of safety relays could be classified into different failure mechanisms. Then, the optimum identification parameters would be selected as prediction variables by Fisher discrimination criterion, and the failure threshold was defined. On this basis, we build the model of BP Neural Net Time Series to train the prediction variables and predict the change trend of variables. By comparing the prediction variables with failure threshold, the remaining life of relay is obtained. Finally, contrasting the real life of the failure relay with the life predicted by the regression models, we come out the precision of the prediction model. Before predicting data, we use the way of eliminating abnormal data, smoothing line and methods such as wavelet transform to eliminate noise. It will improve the accuracy of life prediction. This study can realize the accurate forecast of safety relayÃ¢â‚¬â„¢s life in practical simulation.
Study on the Way of Ensuring Ride Stability of Railway Freight Cars
Dynamic performance is the basis of ensuring the safe and reliable operation of railway freight cars. As the customerâ€™s demands and technology advance on railway cars grow, the carrying capacity and operating speed of cars also increase, forming two directions of heavy haul and high speed in development of railway freight cars. The urgent demand of high-speed freight cars makes the hunting stability become the key factors of ensuring the ride safety of cars. This paper presents the design method, the simulation and test means to prevent hunting instability from occurring on cars under normal operation and provide safe operation. In order to ensure the hunting stability of wagon during operating, periodical detecting on conditions and parameters of parts with key features shall be conducted.
LIDONG LI, KEWEI LYU, XIN LIU, LEI HAN and CHAOYUAN WU
Research on Reliability Modeling for Railway Track Facility-Segment-Line Systems
Reliability of railway track is important for the safety and security of railway operation and control of maintenance costs. This paper develops reliability models for track facility-segment level and improves reliability models for track segment-line level based on the track segment analysis method. The reliability and failure rates of track facilities, segments and lines, which reflect the health status of railway track, are calculated with the method of Markov chain. The reliability hierarchy models for railway track facility-segment-line systems are formed at last.
Development of Wagon Condition-Based Maintenance System Based on Big Data Analysis-Services Platform
With new type of wagons have been continuously put into operation and existing railway wagons have been finished the transformation, problems in the plan maintenance mode are increasingly prominent. Therefore, based on 4T systems and the combination of advanced prognostics and health management concepts, with existing railway information and monitoring system, this paper used big data technology to establish large data technology analysis services platform of wagon condition-based maintenance system, and the related data of railway wagon maintenance is deeply excavated. And it provides technical support for railway wagon condition-based maintenance.
Research on Detection of Rail Temperature Stress Using Rail Vibration Characteristics
In this study, a finite-element model of axial loads on a rail in a ballastless track was established based on the theory of vehicle-track coupling dynamics into consideration of the rotational inertia and shear deformations of the beam. Based on the theoretical analysis, the rail vibration characteristics were studied using an experimental model under different forces. As a result, the main vibration characteristics of the rail were obtained. The model employed is found to be useful for studying the relationship between the temperature stress and the vibration characteristics of the rail. Furthermore, it can be applied to predict the safety and reliability of a rail under different temperature stresses using the rail vibration characteristics.
CHONG LIU, JUNSHENG LIANG, TONGQUN REN and DAZHI WANG
Research on Prediction Models of Track Geometric Irregularity
Rail track geometric irregularities are the concrete embodiment of track structure deterioration, and give an expression to the comprehensive performance of track members. Quality Index (TQI) could reflect the change of track geometry state. It is a time series changed with time. In this paper, the Gray-Weibull model is developed to model over TQI and compared with conventional non- equidistant GM (1,1) model. Effectiveness of the prediction model is validated by the actual data of Ning-Hang Line K219.2~K219.4 unit section. The results show that the Gray-Weibull model is with higher prediction accuracy, which guides the maintenance of railway track.
Research on Health Management Methods of the PEM Fuel Cell Locomotive Based on the Voltage Uniformity
The proton exchange membrane fuel cell, with its advantages of high power density, low pollution, low noise and high efficiency, has attracted much attention and is a very promising internal combustion engine. So far, several countries or regions successfully developed fuel cell locomotives. However, the fuel cell is not market-oriented or wide range of application. Fuel cells and locomotive maintenance system has just started. Its poor reliability and short service life problems have been hindering the widespread use of proton exchange membrane fuel cells. Health management is an effective solution to ensure the safe operation of fuel cell. Many serious faults can be effectively avoided by preliminary health assessment and prediction. Based on the research results of experts from home and abroad, this paper has made some further research. In this paper, BP network algorithm for establishing the relationship between the respective input signal and the output voltage, and a voltage is proposed to balance the fuel cell as an indicator of health management strategies. In this paper, a new way of strategy is put forward for the health maintenance and life extension of the proton exchange membrane fuel cell for locomotive.
Full Life Management of the Electrical Components Based on Safe Running of EMU
This article mainly describes full life management of the electrical components of EMU. At the beginning of the design, this paper will determine the preliminary life of the electrical components; in the process of running, this paper is to carry out failure statistics, draw the failure curve and analyze the relationship between failure and life according to different environmental conditions and operation and maintenance systems; during the maintenance, field work is conducted on the sub-assemblies for maintenance to know the conditions of each component after many years of running; the electrical components whose life is close to the end are selected to judge the remaining life through many tests such as accelerated weathering and vibration impact; through all the methods mentioned above, the proper life of each component in the electrical system is thus determined. After the determination of life, manage and record the running time, maintenance and replacement of each component etc., replace the electrical components whose life is close to the end and ensure the safe running of EMU in the full life cycle, perfect overhaul specification of EMU electrical components and achieve the unity of safety and economy through full utilization of MRO management system of components.
The Study on the Influence of Toe Load on the Failure of Railway Fastening System in a Thailand MRT Project
The rapid expansion of railway network in Thailand imposes the need for the effective maintenance to ensure system reliability, availability and maintainability (RAM). In modern railway track work, different components, e.g. ballast, track plinth, fastening system, rail and etc. form a complex system. Each component is designed and customized for specific functions. Failure to fulfill their function will cause the system unable to perform expected task or even system break down. One critical component in the railway track work is the clip whose function is to properly maintain the rail in lateral and longitudinal position and at the same time allows some degrees of the deformation of the rail to accommodate daily thermal expansion. One typical criterion to ensure proper function of the fastening system is specified toe load values of the clips after track work installation. In the service, the clips are potentially subjected to both normal fluctuating load and high dynamic load, e.g. impact load due to track irregularities, welded joint and etc. which can cause fatigue failure. If the damage cannot be observed and corrected in time, the clip could break and yield serious consequences. Even though the track work is properly installed, toe load of clip could differ by more than 50% resulting in large difference in initial stress condition. Clips with high initial stress could be anticipated of fatigue failure in the service. This present work is intended to study the influence of toe load on fatigue resistance of clips. Based on measurement data performed on site in a MRT construction project in Thailand, both fatigue experiment and simulation were performed to evaluate the life time of clip. The finding from this experiment can be used as a guideline to schedule proper maintenance plane to ensure the structural integrity of railway track components.
Multiple Fault Diagnosis and Prognosis of Chinese Train Control Systems
In railway transportation, prevention or reduction of delays due to any equipment failure is becoming ever more crucial. This work presents a D-matrix-based multiple fault diagnosis of Chinese train control system equipment. It integrates rough set and Huffman coding-based heuristic functions to obtain the near-optimal test sequences. This facilities to construct test sequences with the balance between precision and minimum expected testing cost. By embedding D-matrix with reliability parameters and probability of missing detection and false alarm, a continuous time Bayesian network-based prognosis algorithm is used to compute the failure probability distribution with time and evaluate the failure trend. A CTCS equipment is used to demonstrate the efficiency of the proposed multiple fault and prognosis algorithm.
Research on Integrated Monitoring Display System of the Train
As the interface for human-machine interaction of health monitoring system of train running, the train monitoring display system can fulfill many functions such as the display of running safety information, failure information and maintenance data as well as failure record and storage etc. The existing train monitoring display device mainly comprises of 4 dependent devices. In recent years, due to the development of running safety technology and other test and control systems, there is an increasing number of cab consoles mounted with the monitoring display device which makes the cabs and consoles more crowded. In addition, many repeated contents on each display device add to the visual burden and exhausted working of the driver which could affect running safety. Therefore, it is of vital significance for ensuring the normal running and running safety of the train to carry out a prospective and intensive study on the train monitoring display system. In this paper, the concept of system integrated design is initially applied in the design of train monitoring display system which integrates above 4 system monitoring display devices function into the train network control system. The hardware frame adopts a degraded paralleled redundancy. For display, a big dimension LCD is adopted which boasts a higher resolution, a more exquisite and clearer image display featuring partition drive and the function of display redundancy control. To sum up, in the aspect of hardware frame, the creative design adopted endows the system with higher reliability, safety and intelligence compared with the prior system. Regarding display, a big dimension LCD is initially applied. Its HMI interface developed under the guidance of the theory of human-machine engineering features a complete function and reasonable distribution of information which reduces time and energy consumption of the driver on information management and integration in running and thus improves the running safety. A revolutionary transform of the monitoring display system in the field of rail transit is finally realized.
The Train Structural Health Monitoring System Based on Internet+
Design an intelligent Structural Health Monitoring System combined with the Internet+, according to the characteristics and demand of the vehicle health monitoring. This system is composed of acquisition subsystem, wireless transmission subsystem and monitoring terminal subsystem. Use signal collection technology to collect those important parts of the vehicle and then transmit them to the train network system. Use TD-LTE network system to transmit the information to the ground database in real time and quickly to establish a digital and information file with long-time structure. Use monitoring terminal to carry out remote and real time monitoring of the vehicle status. Through analyzing and processing the data and mining for big data, you can make safety evaluation and health diagnosis, judging its damage degree and damage position, as well as make real time forewarning and forecast and supply them to personnel responsible for maintenance to carry out specific conservation and maintenance. The system realize the digital and information of the structure status; promote active maintenance and management progress, which is of great significance to improve and guarantee the monitoring, maintenance and management level of the structure operation, reduce workload, reduce the risk of operation safety during the whole lifetime and prolong its safe service lifetime.
Sleep Monitoring System for Railway Drivers
Safety is the first priority of railway transportation management, so when working in the lane, drivers must maintain a high degree of attention, which needs to ensure the drivers time to rest, and there needs an evaluation of detection means and an objective results after drivers getting into a sleeping space of independent. In order to achieve this purpose, this paper designs a low load of the sleep monitoring system, which includes four parts as following: data acquisition device based on the pressure-sensitive cable, the data analysis system based on ARM platform, the apartment management software based on C/S framework and network retrieval system based on B/S framework.
Fault Diagnosis, Life Prediction and Maintenance Decision Based Train Monitoring Data
With the rapid development of the domestic rail transportation, the comfortable and punctuality of train running is becoming the focus. Therefore, how to deal with the occurrence of the failure and maintenance decisions, and improve the customer satisfaction, it will be the major problem which the vehicle manufacturers have to face.
Study of EMU Train Prognostic and Health Management System Based on Big Data Technology
This paper mainly discusses the construction and application of EMU train Prognostic and Health Management System (PHM) based on big data technology. Take clustering algorithm for example, which is one of the commonly used data mining algorithm, to explore predictive maintenance of bogie systemÃ¢â‚¬â„¢s axle temperature. Based on this research, we attempt to point out this systemÃ¢â‚¬â„¢s significance for EMU train's operation safety.
SHICUN ZHANG, HEYONG SUN, WEI HAO and CHUAN WANG
A Four Step Method for Railway Operators to Implement Condition Based Maintenance Effectively
With the lately evolution in sensor technics combined with the available fast processing of big data, condition based maintenance comes technically to realization. However, railway undertaken are struggling in implementation. It is not always obvious which parameters are useful to be observed in order to perform a fast and easy realization and still maintain a positive business case. In addition, current maintenance manuals of vehicles, actual homologation processes, hence legal terms from authorities and the trend to separate wayside and trackside responsibilities do not support this development. Therefore, decision factors, strategies and categories are shown out of a holistic railway system approach.
Railway Condition Monitoring, Present and Future
Monitoring the conditions of railway asset is essential for ensuring the railway safety. This paper presents the application of condition monitoring technologies to vehicle suspensions and railway track. The theory, concepts and implementation status are summarized with the key trends appeared in recent international railway conferences and discuss with a future look.
A Certifiable Framework for Maintenance Strategy Including CBM
The scope of this paper is to provide an E2E perspective of SHM as an integrated system element of an integrated system health monitoring and management (HMM) system. The paper will address two main topics 1.) The importance of a diagnostics and prognostic requirements specification to develop an innovative health monitoring and management system 2.) The certification of a condition based maintenance system aiming for a maintenance credit as integral part of the maintenance strategies. The development of a maintenance program which is based on combinations of different types (Preventive, CBM and Corrective Ã¢â‚¬Â¦) of maintenance strategies for different subsystems or components of complex systems like an aircraft to achieve the most optimized solution in terms of availability, cost and safety / certification is a real challenge. Maintenance Strategy plans most cost effective maintenance type for each fault of a sub-system in such a way that availability and safety are optimized. The maintenance strategy must satisfy the technical-risk and cost feasibility of the maintenance program.
Research on High-speed Train Intelligent Prognostics and Health Management System
In order to ensure the operation safety and to improve the operational efficiency has received high level concern, a planning of high speed Train Intelligent Prognostics and Health Management system Ã¯Â¼Ë†TIPHMsÃ¯Â¼â€° has been presented to optimize the limitation of the current condition monitoring means on trains as well as to conduct the active mode adopted in daily maintenance. With TIPHMs, multi-parameters data of the trains on operation can be acquired. Then the health condition of the vehicle or critical components can be assessed. Besides, the evaluation accuracy can be improved due to the two-factor authentication between the vehicle-mounted system and the ground monitoring system. Furthermore, the lifetime prediction of the vehicle system or components can be conducted. Finally, the optimized maintenance strategy can be given by integrating other information. The research of TIPHMs will have promising application in railway.
ZHIQIANG ZHANG, CHANG PENG, HAITAO LI and NING LI
Application of Improved Reliability and Technique Centered Maintenance in the Reliability and Healthy Management for Equipment in High Speed Railway
China high-speed rail operating & maintenance modernization is the inevitable choice after high-speed operation range scale. This paper proposes RtCM, a new pattern, it based on the application practice and research of Reliability &Technique centered maintenance (RtCM), it is a systematic engineering method used to determine the maintenance requirements of high-speed railway equipment in their present operating context. RtCM will achieve obvious optimization in analysis efficiency, applicability and application.
Bondline Degradation Monitoring and Remaining Strength Estimation via an Electromechanical Impedance-Based Method
Bondline integrity monitoring and assessment is one of the most critical concerns for mechanical and aerospace structures, such as aircraft or high-speed trains, up to date. Due to the lack of confidence on the integrity of the bondline both during fabrication and service, the industry standards and regulations require assembling the composites using the inefficient Ã¢â‚¬Å“black-aluminumÃ¢â‚¬Â approach, i.e., drill holes and use fasteners. Current state-of-the-art non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques do not provide mature solutions on the issue of bondline integrity monitoring. Therefore, the objective of this work is to investigate the feasibility of a novel monitoring approach that is based on (i) embedded piezoelectric sensors into adhesively bonded joints and (ii) appropriate diagnostic and prognostic techniques for determining the bondline integrity and estimating the remaining strength of the bondline. The proposed method makes use of an electromechanical-impedance (EMI) based method, which is a rapidly evolving Ã¢â‚¬Å“localÃ¢â‚¬Â approach within the SHM family of methods. By embedding piezoelectric micro-sensors into adhesive bondlines, measuring the EMI spectrum of the sensors, and employing diagnostic/prognostic algorithms the strength of the adhesive joints may be estimated. The obtained results demonstrate the potential of the approach in providing increased confidence on the use of bonded joints for mechanical and aerospace structures.
Intelligent Remote Monitoring and Fault Diagnosis System
This paper mainly discusses remote transmitting the rail vehicle data, which includes real-time data, fault and alarm information, maintenance records and so on, by 3G / GPRS, 4G, Beidou short message and many kinds of WLAN wireless transmission to a server on the ground. Meanwhile, it receives confirmation order, reply order and orders from the ground. This is the method realizing vehicle ground interaction. Through data acquisition, front-end processing, remote data transmission, ground integrated information processing system, data mining and diagnosis technology, this system provides the quality of the track vehicle data, which is the system diagnostic basis of a correct solution. It is possible to provide detailed data, fault prediction information and related reports of the quality of rail vehicles. The framework of health diagnosis system, design concepts and user interface, interpretation machine, knowledge base, reasoning machine, agenda, and the rule based expert diagnosis technology for the knowledge acquisition machine are all described in detail. Providing advanced platform methods for the realization of the prospective use of maintenance services, equipment life cycle cost reduction, the efficiency improvement of transport equipment, transport management improvement and other aspects.
Structural Health Monitoring System for a High-Speed Railway X-Arch Bridge using Wireless Networks
Zhaoqing Xijiang steel box x-arch bridge on the Nanning-Guangzhou railway is located at the mountain area near the southern coast of China. The main span is 450 m, which is the longest among the same type of bridges. The average occurring frequency of typhoon is about 3 times per year, and the maximum wind speed exceeds grade 12 (32.6 m/s). To monitor the behavior of the bridge under the train and environment actions, an online health monitoring system based on DASP-MTS (Data Acquisition and Signal processing-Monitoring Test System) was established, which can transfer real-time monitoring data to cloud server via 3G wireless network. This monitoring system works in a browser/server frame, providing an easy remote monitoring method. Users can obtain real-time data from this system at any location. Field measurement of wind characteristics are discussed in this paper.
Vibration Characteristics Analysis of the Maglev Vehicleâ€“Switch
Coupling vibration of Maglev vehicle system directly affected the comfort and safety of the train. Aim at vibration issue when the Maglev vehicle get through the switch generated. In the paper, the vibration transfer of vehicle-switch is researched to use experiment approach. The model parameters of switch are measured to apply impact hammer. The vibration spectrum of the maglev train dynamic on-line measurement is analyzed. The natural frequency of track beam is aroused when maglev vehicle diver on the switch in the initial condition. So the coupling resonance caused between vehicle and switch. After improving the turnout stiffness, the resonance phenomenon disappears and the vehicle can be smoothly through the orbit switch.
An Applied Research on Reliability Evaluation in the Train Network System
As the train develops in the direction of high speed, intelligence and comfort, higher requirements are raised on safety and reliable running of the train. The structure design of locomotive becomes increasingly complex and more service information with its variety is offered to the passengers. These factors diversify the equipment in the train network system and the number and variety of control information, monitoring information, and failure diagnose information as well as passengersâ€™ service information that need to be transmitted through train network are also doubled. Therefore, the train network system is the key in the future of train as well as the train stability and safe running. The more reliability the train network system has, the more safely the train runs in addition to the great reduction of commissioning and maintenance costs. Therefore, it is of vital theoretical and practical significance for the design of train network system and even of the complete train to analyze the reliability of the train network system and explore the improved measurements of reliability of train network system. Currently, little systematic reliability evaluation is conducted on the train network system of the existing train, and the introduction on the effect of reliability factors on the train network system is far from specific. This paper is aimed at putting the current train network system in the mainstream into model building and carrying out systematically reliability evaluation in an effort to seek out the factors that affect the system reliability. It sets out to elaborate on the basic theory of reliability and then puts the WTB ï¼‹ MVB network aimed at the current mainstream frame into reliability model building through a serial model, and puts the frame of ETBï¼‹ECN network aimed at the development trend of the next generation into reliability model building at the same time. Finally, the reliability expression of both systems is thus obtained. The main factors that affect reliability of the train network system are obtained through the analysis. The model provides references for the reliability evaluation and active safe operation and maintenance of the train network system, and for further network system design of the existing train.
The Detecting System of Train Derailment
With the development of the high speed railway and urban rail transit, the safety of train running become more important. How to prevent of train derailment was seen as an acknowledged difficulty in researching of railroad. Designing a derailment detecting system with ultrasonic ranging according to the fixed geometric relationship between bogie and rail. The detecting system based on different wheel pair tread to forecasting train derailment and link with emergency braking system. The destination of train derailment design is to decrease and avoid the serious traffic accident of train derailment. The system use train speed, railroad condition, train derailment process record to get the statistics rule of train derailment. The data of rule of statistics is in favor of train derailment research project.
LIYUAN ZHU, MINGSHUN ZHANG, LIANG ZHAO and FUZE SONG
FEM Simulation Study for Damage Acoustic Emission Signals on Composite Laminated Plate
Composite materials are widely used in high-speed rail transportation, but the multiple damage may include matrix cracking, matrix/fiber debonding, delamination and fiber breakage which can be caused by impacts, fatigue, or overloading in the manufacture, assembly and service process. The type and location of the damage can be identified by structural health monitoring (SHM), thus the occurrence of fatal accidents can be avoided. When any damage occurs in the composite material, different transient non-stationary acoustic emission (AE) signals can be detected. However, the high cost and unrepeatability are the restraining factors of practicality experiment. Therefore, the simulation study has become an effective method to solve this problem. This paper proposes a method to establish a composite laminated plate model with interface by setting cohesive elements. Compared with traditional ways, it greatly improves the facticity of the simulation model. Based on this model, four kinds of AE signals represented four different damages are simulated using the sine modulation signals as the excitation, and the effectiveness of this method is confirmed after doing the frequency spectrum analysis. In addition, the excitation signal is applied on the different depth of the plates, and the sensing signal features are analyzed.
ZHILING LIANG, MEI YUAN, ZONGXIA JIAO and HAN ZHANG
In-situ Fatigue Damage Detection for Railway Structures Using Nonlinear Ultrasonic Guided Waves
This paper presents a damage detection strategy for rail tracks by taking advantage of the nonlinear interactions between guided waves and fatigue cracks. A Local Interaction Simulation Approach (LISA) was developed to achieve efficient simulation of ultrasonic guided wave propagation in railway structures. The stick-slip contact dynamics at the fatigue cracks was integrated into the LISA model using the penalty method and Coulomb friction law. The LISA procedure was coded with the Compute Unified Device Architecture (CUDA), which enables the highly parallelized supercomputing on powerful Graphics Processing Units (GPUs). Guided waves generated at the transmission location propagate along the rail track, interact with the fatigue crack, carry the Contact Acoustic Nonlinearity (CAN) with them, and are finally picked up at the sensing location. Various fatigue crack size cases were simulated to investigate the change of nonlinear spectrum characteristics from the growing damage severity. A damage index was developed based on the nonlinear ultrasonic energy proportion in the sensing signals to monitor the existence and severity of fatigue cracks. This study shows that the nonlinear ultrasonic techniques possess promising potential for the in-situ health monitoring of railway structures.
Verification of Snow Model for Particle Simulation for Train Safety
In this research, a new snow model for trainÃ¢â‚¬â„¢s safe driving made by the particle method is proposed. Snow is assumed as a Bingham fluid. Verification of this special non-Newtonian fluid is done, as well as a good agreement is obtained by comparing the MPS (Moving Particle Semi-implicit) numerical result with referential result. Furthermore, a collision model between train and snow is built; Bingham snow model is compared with Newtonian snow model as well. A reasonable impact phenomenon occurs by introducing the present Bingham snow model.
Extreme Function Theory for Novelty Detection: A Case Study for Vehiclesâ€”Guideway System
This paper focuses on detecting the irregularity of track geometry using the extreme value theory. The vehicleÃ¢â‚¬â€œrailway system is simplified into a system of 2-degree-of-freedom motions, and the random dynamic load input is the displacement of vehicle caused by the original defects or deformation of rails. Blackman-Turkey method is adopted to cope with the surrogate model and to generate the dynamic response of vehicle. The responses of vehicle are used for observations of normal and abnormal models to conduct novelty classification by the extreme value theory. The difference between normal and abnormal models is converted to the distinction of the tail distributions, which converges to the generalized extreme value distribution regardless of the parent distribution. The parameters of the generalized extreme value distribution are estimated with the method of maximum likelihood. The threshold for irregularity classification is estimated according to the pre-desired confidence level. A case study of running trains with the dynamic response to vertical profile irregularity verifies the method well.
FBG Temperature Sensor Data Processing System Based on LabVIEW
Train and high-speed rail tracks are susceptible to different damage modes such as cracks, corrosion, and degradation. If damage is left undetected, these initial damage sites can propagate and cause track failure and derailment, similar to the 2016 Amtrak train derailment incident in Kansas. However, damage sites in these tracks can be hard to detect, particularly because they start small and can be hidden from plain sight (e.g., due to dirt, debris, and corrosion that would otherwise obstruct its view). Therefore, the long-term goal is to develop a portable damage detection tool that can scan the cross-section of a track and be able to identify the location and severity of crack damage. As a step towards this goal, this study is focused on using numerical simulations for assessing the validity of using non-contact tomography for track damage monitoring and localization. Specifically, the technique is based on electrical capacitance tomography. A set of non-contact electrodes arranged in a circular ring pattern can be selectively excited using an alternating current signal. By measuring the electrical response at all other electrodes, one can use this dataset for solving an inverse problem to reconstruct a map of the electrical properties of the sensing region (i.e., the area enclosed by the ring of electrodes). Like computed tomography images, the results show an electrical permittivity map of the cross-section. Any localized changes in the permittivity map reveals locations in which there might be damage in the track and is worthy of more detailed assessment. A set of numerical simulation case studies has been done to assess the potential of using this technique for track monitoring. Preliminary results obtained show that this technique was able to detect, quantify, and locate the change in permittivity distribution in the modeled rail track, thereby suggesting its potential as a noninvasive spatial damage detection tool.
Numerical Simulations of Railroad Track Damage Characterization Using Non-Contact Tomography
The progress in the development of sciences pertaining to structural health monitoring has witnessed tremendous growth. Significant progress has been made in finding and locating defects in plate-like and in built-up structures. This paper shall present a potential Ã¢â‚¬Å“what nextÃ¢â‚¬Â in the field of structural health monitoring. It will illustrate this with work performed on the wayside monitoring of rail infrastructure. The application of wheel impact load detection or WILD systems to monitor train wheel health condition has generated significant savings and an increasing database of knowledge regarding wheel performance and behaviour. Applications of the WILD systems have so far been limited to assessing wheel health and determining which wheels are too hazardous to be in operation. This paper will show how a defective wheel can be identified by wayside monitoring. Once these defective wheels are identified, it is then important to determine if we can leave this defective wheel to continue operation. This decision can be assisted by integrating the engineering data into an economic model. The application of an economic feasibility study on the wheel removal protocol showed the relative savings obtained from timely removal of train wheels with defects. This is an alternative approach to the current wheel removal protocol which employs a three stage wheel monitoring and maintenance procedure dependent on the impact load levels.
Integrating Cost into Rail Wheel Maintenance
The rapid advancement of Information and Communication Technologies (ICT), sensory technologies, and the integration of advanced big data analytics into industrial entities has brought both opportunities and challenges. The companies are facing challenges in the new competitive business environment in dealing with big data issues for rapid decision making, improved productivity, and sustainable value chain services. U.S. has been driving the Cyber Physical Systems (CPS), Industrial Internet, and Advanced Manufacturing Partnership (AMP) Program to advance future manufacturing. Germany is leading a transformation toward 4th Generation Industrial Revolution (Industry 4.0) based on Cyber-Physical Production System (CPPS). China has just launched 2025 Plan and Internet Plus to strengthen manufacturing and accelerate service innovation. It is a clear trend that as more predictive analytics software and embedded IoT are integrated in industrial products and systems, predictive technologies can further intertwine intelligent algorithms with electronics and tether-free intelligence to predict product performance degradation and autonomously manage and optimize product service needs. This paper will address the trends of big data analytics and cyber-physical systems for prognostics and health management (PHM) of future railway transportation systems. First, the systematic 5C architecture for CPS-enabled intelligent operation and maintenance (O&M) is discussed. Then a description of analytical tools and technical concepts in CPS is presented with case studies is presented. And finally, the benefits, future trend, and challenges for CPS applications in railway systems are concluded.
Recent Advances in Industrial Big Data Analytics and Cyber-Physical Systems for High-speed Railway Transportation Systems
The running environment of high speed EMU (Electric Multiple Units) is complex and the electromagnetic interference is serious. Compared to electric type sensors, FBG (Fiber Bragg Grating) sensors have immunity to electromagnetic interference, less wiring and easy distributed networking features. FBG sensors are used for real-time temperature monitoring of EMU traction transformer and traction converter, and the abnormal temperature during operation cause alarm. Since the large temperature measuring points and the long monitoring time, the amount of recorded data is huge. Considering the real-time, integrity and maintainability of monitoring data, the data processing strategy for real-time storage, out of limit alarm, remote transmission and server data statistics and management is developed. ENLIGHT software is used for data acquisition, real-time storage and out of limit alarm of interrogator SM125. HUAWEI EM660 3G communication module and TeamViewer software are adopted to realize remote data transmission. In the receiving server, based on LabVIEW and Access database, the temperature history data analysis system is designed to realize the temperature data display, extreme values statistics and historical data query. The system is simple and reliable, which can be used in the long-term monitoring and data processing of FBG sensors.
ZONGCHANG LIU and HOSSEIN DAVARI ARDAKANI
High Speed Mobile Thermal Scanning for Qualitative Defect Detection on Underside of a Flat Plate
A thermal line scanning method is applied to inspect defects at varying depths on the underside of a steel plate. Through the use of computational simulations, the transient temperature response of the plate surface for high speed mobile heating is shown to be similar to that produced by stationary heating. High speed line scan thermography could potentially provide a basis for the rapid in situ detection of underside material-loss defects in steel rail.
Study on the Dynamic Response and Reasonable Design Parameters on Bottom of Tunnel Structure under Heavy Loading
In this paper, a coupled numerical model of heavy-haul railway tunnel structure and surrounding rock was established, based on the theory of dynamic finite element. Train load in the model was simulated by excitation function. The paper analyze the influence of different design parameters, in terms of rise-span ratio and thickness of packing layer and invert, on the characteristics of dynamic response in heavy-haul railway tunnel structure. The result showed that dynamic response of whole bottom structure of heavy-haul railway tunnel is much more significant than that of normal railway tunnel, which would bring about more disadvantageous consequences to structural stability of tunnel. The peak value of different mechanical index as well as its position have been found through research. Further research studied reasonable planning parameters of bottom structure in double track railway tunnel under the heavy load by setting typical condition. The study showed reasonable value of rise-span ratio and thickness of packing layer and invert is 1/10~1/11, 1.2~1.3m and 40~50cm respectively, which could reduce dynamic response and improve stress states of double track railway tunnel under the heavy load.
LIMIN PENG, CHENGHUA SHI, MINGFENG LEI and XIAOKANG FU
Develop a Concept of Operations for Railroad SHM System
High speed trains operate in harsh and varying operations environments in its service life. Components of high speed train are constantly under severe stresses due to varying loads, varying temperatures, interface conditions, and due to structural design that leads to high stress regions at different locations on the structure. High speed trains are considered as highly dynamic and critical structure that need continuous monitoring of health of different components of the structure. CRRC and Acellent Technologies have developed a concept of operations (CONOPS) of SHM system for monitoring different components of the train structure. This presentation includes case studies of SHM system developed for monitoring critical structures in other industries and the proposed CONOPS for monitoring critical components in a high speed train system will be presented.
HOWARD CHUNG, FRANKLIN LI, CAS CHEUNG and AMRITA KUMAR
Advance of Safety in Japanese Railways; Teachings from Accidents and R/D of New Safety Technologies
The safety of Japanese railway system is very high, only 0.6 accidents occurs every million km-train-run. Such high safety level have been achieved by teachings from various previous accidents. In this paper the author introduces the history of previous serious accidents and the countermeasures against them, such as the developments and practical uses of new safety technologies. And then establishment of the governmental accident investigation organization in Japan and the outline of it are introduced with some examples of its investigation results and the countermeasures especially concerning condition monitoring.
Evaluation of Sensing Technologies on Railway Vehiclesâ€”With Focus on Optical Sensors
Sensing technology covers a wide range of functionalities, such as electromagnetic sensors (radar), optical sensors (imaging technologies, lidar, laser and infrared) as well as acoustic sensors (ultrasound), each of which are applied for specific uses. In recent years, sensing technologies have been widely adopted in various sectors, including the automotive, aviation and railway industries. Within the scope of this work, an investigation is carried out in order to determine the requirements, as well as potential applications, for the use of sensing technologies in the monitoring of railway vehicles, infrastructure and the areas surrounding railway vehicles. An advantage of optical sensors is their ability to monitor the status of detail-rich systems. The applications of high-dynamic-range CMOS imagers (HDRCÃ‚Â®) cover a large range of fields with high reliability and performance. In contrast to the traditional discrete contact sensors, which require installation at several detection points, HDRCÃ‚Â® cameras are capable of monitoring multiple components simultaneously with a smaller number of contactless optical sensors. In specific, the application and development of a photometric sensing system for railway vehicles will be proposed and investigated in this paper. The system is to be focused on temperature measurement, safety supervision in industrial manufacturing and vibration detection. In addition, requirements and cases of optical sensor application will be specified. The implementation of this technology seeks to achieve more efficient and economical processes for the production of railway vehicles (e.g. monitoring of highly-dynamic welding and cutting procedures with PyroCam), safety supervision in industrial manufacturing, and condition based maintenance (CBM).
JAN DIRK SCHULZE SPUENTRUP, FRANZ X. HUTTER, MARKUS STROBEL, TIMO STROBEL, ULLRICH MARTIN,
Campaign Monitoring of Railroad Bridges Using Wireless Smart Sensors
This paper presents research results using wireless smart sensors to develop a cost-effective, practical, and portable structural health monitoring system for railroad bridges in North America. The system is designed to enable campaign-style monitoring of railroad bridges under in-service train loads. Validation is carried out on a 94.6 m long steel truss bridge near Chicago, the busiest railroad hub in North America. A finite element (FE) model of the bridge is developed and calibrated using the measured data. Subsequently, the model is used to predict bridge responses at unmeasured locations for varied train loads and speeds. The results from this research provide a technological foundation to develop campaign monitoring as an important tool with which to manage railroad bridge assets.
Reliable Quantification of the Performance of SHM Systems
Structural Health Monitoring has great potential to replace in-service NDT, giving the opportunity to increase intervals between maintenance shutdowns and to have early warning of the need for component replacement. However, it is essential that the performance of the SHM system is thoroughly evaluated to give confidence that it will detect the required defects at an acceptable level of false calls. This is more difficult than the evaluation of NDT methods as the SHM system will operate across a wide range of environmental operating conditions (EOCs). Although damage can be applied to test structures in a laboratory environment to evaluate the performance, it is often prohibitively expensive to comprehensively investigate the sensitivity of damage detection on different damage types, sizes, and locations under different EOC. In this paper, a cost-effective methodology is presented to evaluate the performance and estimate the sensitivity of an SHM system by synthesizing undamaged records collected under varying EOCs and simulated artificial damage signals. We produce the receiver operating characteristics (ROC) of damage detection methods on different synthetic datasets to predict the performance in practical scenarios.
Field Investigation into the Dynamic Response of Steel Sleepers
This paper will report on a series of a field investigation into the dynamic response of steel sleepers and its effects on the ballast in its vicinity. The results presented were obtained from a series of field data collection with revenue trains which defines the uniqueness of this work. This work was conducted on steel sleepers along a section of tangent track and a section of curved track in Whyalla, South Australia in September 2015. The main aim is to establish a basis for the design requirement of steel sleepers. The instrumentation was installed on rail tracks which had narrow gauge steel sleepers. Measurements were taken for loaded and unloaded trains along those instrumented sections. The interaction between the dynamic response of the steel sleeper and its effects on the ballast compactness in its vicinity will be reported. The effects of the mass of the train on these dynamic responses are also discussed.
WING KONG CHIU, GRAHAM TEW and EDDIE BENNETT