On the study of surface wave propagation in concrete structures using a piezoelectric actuator/sensor system

Concrete structures have been used widely in civil infrastructural systems. Due to the complex nature of the microstructure, nondestructive testing (NDT) of concrete inherently imposes many challenges, which can cause severe limitations on the resolution and the sensitivity of the signals observed. In this study, a numerical simulation based on the finite element (FE) model is first performed to investigate surface wave generation and reception using piezoelectric actuators/sensors, especially in relatively higher frequency cases. The results provide a basic understanding of some features of the microstructure effects on the surface wave propagation. Experimental testing is then conducted to validate the numerical simulation. The group velocity dispersion curves of the surface waves, which are very useful for future damage detection in concrete materials, are obtained from both numerical and experimental results. The good agreement shows the great potential and feasibility of using piezoelectric actuators/sensors to generate and receive surface waves for quantitative damage detection in concrete structures.