Effect of delamination on natural frequencies of laminated FRP composite plate

Abstract

De-lamination is a subtle kind of failure which might be induced during manufacturing or material handling, which causes the layers of a laminated composite plate to detach because of the failure of adhesion between the layers. The existence of de-lamination remains a major concern for design engineers as it affects the performance of the components, therefore its presence has to be detected in advance to take remedial action to avoid the malfunctioning of the structural component. The present work carries the investigation of free-vibration response of laminated FRP composite plate and a plate with de-lamination by developing numerical models in MATLAB environment based on the first order shear deformation theory and worked out through finite element procedure using a two dimensional 8 node element with a 5 degree of freedom for individual node. The effect of various parameters like boundary conditions, location of de-lamination, area of de-lamination, aspect ratio, number of plies and laminate stacking sequence on the free vibration behavior of the plate with an existing de-lamination is also investigated. Finally, the impact of de-lamination on the free vibrational behaviour of FRP laminated composite structures will be numerically identified and explored in depth.