Dynamic Instability of Imperfect Sandwich Laminates by an Efficient FE Model

Abstract

In this paper the dynamic instability of sandwich laminates having inter-laminar imperfection is studied for the first time. An efficient finite element model recently developed by the authors is used for the purpose. The plate model is based on a refined higher order shear deformation theory, where the transverse shear stresses are continuous at the layer interfaces with stress free conditions at plate top and bottom. A linear spring-layer model is used to model the interlaminar imperfection by introducing in-plane displacement jump at different interfaces. It is interesting to note that the plate model having all these refined features requires unknowns at the reference plane only.