“…Tracy and Pardoen [4], Paolozzi and Peroni [5], and Shen and Grady [6] investigated the e!ect of single delamination on the free vibration of composite beams using the &&four region approach''. Tenek et al [7] used a similar approach for the simply supported composite plates. Krawczuk et al [8] studied the in#uence of fatigue cracks and delaminations on the dynamic characteristics of laminated composite plates.…”