Nonlinear dynamic analysis of harmonically excited debonded sandwich plates using finite element modelling

Nonlinear dynamic aspects of a rectangular simply supported sandwich plate with a central penny-shaped debonded zone subjected to harmonic loading have been studied by using the finite element analysis within the ABAQUS code. In order to accurately predict the response of the debonded sandwich plate to harmonic loading, contact-impact and sliding conditions along the damaged skin-to-core interface were imposed in the model via the penalty contact algorithm in the framework of an implicit integration scheme. The relevant qualitative parameters such as frequency response curves, phase portraits and Poincaré maps were extracted from time history signals calculated by the finite element analysis for sandwich plates with and without debonded region. The results of the both plates were compared, to specify the effects associated with the presence of debond on the forced vibrations of the sandwich plate. A wide range of forcing frequencies was applied to illustrate various nonlinear responses occurring in the debonded plate’s dynamics. A considerable influence of contact events within the debonded region on the global dynamic response of the debonded plate subjected to periodic loading was found out. The predictions performed also showed that the finite element model applied would be useful for nondestructive evaluation of defects in composite sandwich plates.