Numerical Simulation of PZT Bonded Reinforcement for Health Monitoring of Reinforced Concrete Structure

Abstract

Structural Health Monitor (SHM) for concrete structure using PZT is under wide interests and investigations. Due to complexity of concrete microstructure and the electric-mechanical coupling effect of PZT, the numerical simulation turns to be a good choice for providing theoretical guidance for study and analysis of such an SHM system. An active sensing diagnostic system for SHM of reinforced concrete has been currently under the investigation. Test results show that the system can detect damages of the structure. To fundamentally understand the damage algorithm and therefore to establish a robust diagnostic mechanism, an accurate Finite Element Analysis (FEA) for the system has been performed. A steel reinforcement bar with surface bonded PZT under a transient wave load is simulated using commercial FE software ANSYS. In the model, the rebar with PZT and epoxy layers is built using 2D axisymmetric type. PZT material property transformation is discussed due to format differences between IEEE Standard and ANSYS. The analysis uses the direct coupled-field analysis module. And material properties such as the Raleigh damping coefficients are discussed. The numerical model has been validated with the experimental testing. The good consistency between simulation and test shows that the model is reasonably accurate. This provides a base for further system optimization. A potential signal improvement method is explored. By changing PZT layout into different configuration, the output signal is increased four to six times larger than the original one.