Multiple reflections of Lamb waves at a delamination

Wave propagation in laminated plates with delaminations was calculated using the semi-analytical finite element method. The visualization results and deeper numerical analyses revealed the following phenomena on the fundamental Lamb modes at delamination re-ions of laminated plates. First, Lamb wave propagates toward the delamination, and then splits into two independent waves at the Entrance of the delamination with no significant reflections. These two waves reach the Exit of the delamination with the different phases and arrival time. Thus reflected and transmitted waves are excited at the Exit. The repetition of such reflections at the Exit causes the multiple reflections at regular intervals corresponding to the delamination size. (C) 2002 Elsevier Science B.V. All rights reserved.