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A Novel, Wireless Acceleration Evaluator Used for Health Monitoring of Aging Structures and Bridges

A. SABATO

Abstract


Control aging structures and infrastructures is of importance as these systems may have economic and strategic relevance. Develop reliable and accurate instruments for monitoring the structural dynamic behavior plays a key role in predicting the onset of possible crisis scenarios. Recent advances in technology have made wireless Micro Electro-Mechanical System (MEMS) accelerometers an attractive tool for Structural Health Monitoring (SHM). In this paper, the Acceleration Evaluator (ALE) - a low cost, high sensitivity, wireless prototype sensor board installing a MEMS-based accelerometer - is used as a stand-alone sensor for the vibration monitoring of largesized civil structures. In particular, two cases of study are reported. The first one consists of the earthquake induced vibration measurements on a real-size lab model. It is a 2,500 Kg, 3 meter high stone pinnacle of the Saint Peter and Saint Paul Cathedral Church (Washington National Cathedral) in Washington, D.C. Data collected using ALE are used for a back to back comparison with those recorded with wire-based, high-sensitivity devices. The evaluations carried out in time and frequency domains (e.g. peak ground acceleration, Arias’ intensity, and excited frequencies) are used to determine the measurements accuracy in comparison with standardized and wellknown devices. The second analysis is performed on a 104 meter pedestrian deckstiffened arch bridge, located on the Princeton University campus in Princeton, NJ. The study aims to validate ALE performances in a real-world scenario. Recorded data are analyzed and compared with those reported in literature studies for the bridge. The results from both tests are examined to prove that ALE can be used as vibration monitoring devices to detect accelerations having amplitude in the order of 10-2 m∙s-2 (ambient vibrations) as well as accelerations having amplitude in the order of 100 m∙s-2 (strong earthquakes). To conclude, the future works on the sensor board are described.

doi: 10.12783/SHM2015/120


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