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

An active sensing diagnostic system using Piezoelectric (PZT) for Structural Health Monitor of reinforced concrete has currently been under investigation. As an embedded system, it is good for structural health monitoring of the locations that can't be easily accessed, such as bridge footing areas or piles. To fundamentally understand the damage algorithm, an accurate Finite Element Analysis (FEA) for the system has been performed. In the simulation model, the rebar with PZT and epoxy layers is built using 2D axisymmetric type. The analysis uses the direct coupled-field module. 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 testing shows that the model is reasonably accurate, which provides a base for further system optimization. A potential signal improvement method is explored. By changing the PZT layout into a different configuration, the output signal is increased to four times larger than the original one. Further simulation analysis is made for concrete structure with debonding damage. The results from simulation are consistent with test ones. It shows that the output sensor's amplitude increases potentially with the debonding size.