Dynamic instability of imperfect laminated sandwich plates with in-plane partial edge load

Abstract

Dynamic instability of laminated sandwich plates having inter-laminar imperfections with inplanepartial edge loading is studied for the first time using an efficient finite element platemodel. The plate model is based on a refined higher order shear deformation plate theory, wherethe transverse shear stresses are continuous at the layer interfaces with stress free conditions atplate top and bottom surfaces. A linear spring-layer model is used to model the inter-laminarimperfection by considering in-plane displacement jumps at the interfaces. Interestingly the platemodel having all these refined features requires unknowns at the reference plane only. However,this theory requires C1 continuity of transverse displacement (w) i.e., w and its derivatives shouldbe continuous at the common edges between two elements, which is difficult to satisfy arbitrarilyin any existing finite element. To deal with this, a new triangular element developed by theauthors is used in the present paper.