Dynamic behaviour of sandwich plates containing single/multiple debonding

Debonding is one of most severe defects associated with sandwich composite structures. The damage inflicted on debonding may lead to the significant degradation of the load carrying capacity of sandwich structures and affects their mechanical behaviours. Free vibration analyses of sandwich plates with honeycomb and PVC foam cores containing single/multiple debonding are carried out. Dynamic characteristics such as natural frequencies and corresponding mode shapes of sandwich plates with and without debonding are calculated using the commercial finite element code ABAQUS. Parametric studies over a wide range of size, location and number of debonding zones to examine the influence of these parameters on the overall dynamic behaviour of the damaged plates are performed. As a consequence, natural frequencies and mode shapes are being calculated as functions of these parameters that enable to draw conclusions concerning the debonding influence.