Evaluation of Cracks in Elastic Media using Surface Signals

This paper provides a theoretical study of quantitatively identifying cracks in plane elastic media from surface signals induced by a piezoelectric actuator. The surface signals are used as the boundary condition of the problem to generate a reverse wave field, which represents the scattered waves from the cracks. An imaging technique is then used to determine the sizes, shapes and positions of existing cracks based on the determined scattered waves. Numerical examples are provided to show the feasibility of using surface signals to characterize embedded cracks.