Finite Element State-Space Model of Edge Initiating Localized Interfacial Degeneration of Damped Composite Laminated Plates

Abstract

Abstract In presence of commonly encountered edge delamination problem, a new finite element formulation to examine the effects of a localized interfacial degeneration on the dynamic performance of the cross-ply laminated composite plate adopting the state-space approach is carried out. The stiffness term of the laminate is constructed via the assemblage of the local contribution from each ply sub-element. This involves also the inclusion of an interface layer employing the virtually zero-thickness formulation to model the interfacial degeneration. In addition, the proportional damping and kinematically consistent mass matrix are expressed to form the complete governing formulation. To invoke interfacial degeneration, the degenerated areas are defined from the edge propagating inwards in a localized manner. As the degenerated area of the interface increases, a decreasing pattern is observed in the natural frequency, damped frequency and damping ratio of the plate whereas there exists a rise correspondingly in the loss factor.