Experimental Investigations of Damage Detection in Laminated Composite Plates by Ultrasonic Lamb Waves

The objective of this paper is to study the feasibility of detection and characterization of damage in glass fiber composite laminated plates using S0 Lamb waves. The characterization of this waves is first clarified experimentally by plotting these dispersion curves and their attenuation. The aim of the second part of this work is to investigate the use of the S0 Lamb waves for the detection of damages. The influence of parameters such as the damage size and position in thickness was studied. It has been found experimentally, that the amplitude of S0 Lamb waves decreases with a time shift and its frequency spectrum changes in the presence of damage. The rate of those changes is related to the increase in defect size and the damage location.