Experimental Research on Multi-Damage Detection of Metal Plate Structure Using Lamb Wave

This paper presents a new method for multi-damage detection of metal plate structure by using a wavelet relevant and elliptic line method.Using the Lamb wave propagation characters in the plate structure,the PZT patches are adhered on the surface of an aluminum plate structure to be used as actuators and sensors,Lamb waves are emitted and received by the PZT patches to detect damage in the structure.By the experiment of artificial holes,which are used to simulate the damages in the plate structure using active Lamb waves,the prototype and damaged signals are compared to set up an index for the damage detection.This paper obtains the propagation velocity of Lamb wave,the wavelet transformation results and the arrival time delay of sensing signals before and after damage,also the damage positions in the experiment are received,and they accord well with the actual damage positions.Active Lamb wave monitoring technology can effectively identify damage of plate structure,therefore,it is suitable for damage identification and health monitoring of sheet metal structure.