Geometrically nonlinear transient analysis of delaminated composite and sandwich plates using a layerwise displacement model with contact conditions

Abstract

In the paper, a computational model for the transient response of laminated composite and sandwich plates with existing zones of partial delamination, subjected to dynamic pulse loading is proposed. Laminated composite and sandwich plates are modeled using the extended version of the Generalized Laminated Plate Theory. For the numerical solution, the finite element method with layered finite elements is used. Delamination between individual layers is considered as discontinuities in the displacement field using Heaviside step functions. Since the status of delaminated layers may change in dynamic loading conditions, leading to the so-called "breathing" phenomenon, contact conditions allowing for the opening/closing of delaminated layers are proposed. Nonlinear kinematics in the sense of small strains and moderately large rotations is accounted for according to the von Karman assumptions. The material of the individual layers is assumed as orthotropic and linearly elastic. The governing spatial temporal partial differential equations are integrated in time by means of the implicit Newmarlc's method. After verification of the proposed model for intact plates, the effect of the size and the position of embedded delamination zones on the transient response of geometrical nonlinearity of composite and sandwich plates is investigated numerically by means of a number of numerical applications.