Influence of higher and sub harmonics in time reversed Lamb wave generated and sensed using de-bonded piezoelectric wafers

摘要

Time reversed lamb wave based damage detection is very suitable for online Structural Health Monitoring (SHM). Non linear higher and sub harmonics are generated in the Lamb waves which are generated and sensed using partially de-bonded piezoelectric wafer transducers (PWT) from the host plate. Experimental and numerical studies of the influence of higher harmonics in time reversed reconstruction of Lamb wave in an aluminium plate are presented in this work. 2D finite element simulations are carried out using de-bonded actuator and receiver separately and the influence of actuator de-bonding is found to have more influence on time reversed reconstruction. Experiments are done for transducer de-bonding and the influence of Lamb wave amplitude for non-linear interaction is studied. Influence of de-bonding length on change in reconstruction is also studied.