Effect of Temperature on Time Reversibility of Lamb Wave in Thin Plates with Surface-Bonded Piezoelectric Wafers

Abstract

It is important to understand the effect of temperature on time reversibility of Lamb waves as the time reversal process is widely used as a baseline free method for damage detection in thin-walled structures, for which the temperature invariance of time reversibility is an essential requirement. In this work, the effect of temperature on the time reversibility of the Lamb wave in an isotropic plate is studied experimentally for different excitation frequencies. The experiments are performed at three different temperatures. The time reversibility is computed using the similarity index, obtained from the L2 error norm of the reconstructed signal with respect to the original input signal. The study has revealed that there can be a significant change in the time reversibility due to the temperature variations. However, at the best reconstruction frequency corresponding to the maximum similarity index (a concept proposed recently by second authors group), the variation of the similarity index with temperature is insignificant.