Finite element dynamic analysis of laminated composite plates with multiple delaminations

A simple multiple delamination model is developed for the dynamic analysis of multi-layered laminated composite plates having arbitrarily located multiple delaminations. The displacements of any sub-laminate are expressed with respect to the mid-plane of the original laminate for finding the stiffnesses of the corresponding sub-laminate. The finite element dynamic equations are accordingly derived based on eight-noded isoparametric quadratic elements, assuming the first order shear deformation of each lamina. The present results compare well with those existing in the open literature. Several parametric studies are carried out to investigate the dynamic behaviour in the presence of single and multiple delaminations. Numerical results for free vibration and transient response are presented both for single and multiple delaminated plates with various boundary conditions, stacking-sequences and other geometric parameters.