Analysis of Lamb Wave Excitation by the Partly Debonded Circular Piezoelectric Wafer Active Sensors

摘要

The aim of the present work is the development of mathematical models for simulation and analysis of elastic waveguides with piezoelectric wafer active sensors (PWASs) generating Lamb waves, taking into account the partial debonding. The continuous wavelet transformation is applied to the recorded signal in order to identify the debonded part of the investigated PWAS. More specifically it is used to compute the carrier frequency of the generated wavefield which could significantly differ from the central frequency of the input signal especially in the case of a debonded PWAS. A carrier frequency shift both in the time and frequency domain in the case of debonded PWAS is to be observed due to potential non-linear contact effects such as coming from chattering. It was revealed that both carrier frequency shift and its time of arrival depend on the shape of the debonded part of the PWAS.