Interaction of guided Lamb waves with an asymmetrically located delamination in alaminated composite plate

Abstract

Propagation of the primary anti-symmetric Lamb mode(Ao) in an asymmetrically delaminated cross-ply laminate has been studied through both numericalsimulations and experiments employing the air coupled ultrasonic technique. When theAo mode interacts with the entrance and the exit of an asymmetrically located delamination, in additionto Ao, a mode converted to the primary symmetric Lamb mode(So) also propagates in each of the two sub-laminates as well as the main laminate. These Lambmodes propagate independently in each of the sub-laminates. In addition, turning modes(i.e. the mode propagating in one sub-laminate interacts with delamination edge and startspropagating in the other sub-laminate) and a mode converted turning mode (a newmode is generated during the interaction of turning mode with delaminationedge) were also observed in the numerical simulation. The presence of the ‘modeconverted turning modes’ was also validated through the experiments in this study.