FE Modelling and Analysis of Mixed Mode Delamination in Composite Laminates

Abstract

A composite is a structural material that consists of two or more constituents combined at a macroscopic level and not soluble in each other. The advantages of composites over conventional materials are its light weight, high strength, design flexibility, dimensional stability, etc. Although Composite materials are advantageous than conventional materials, there are some defects in composite materials too, which are Fibre-matrix debonding, fibre misalignment, Delamination, Matrix cracking, Impact damage, etc. Among these defects, Delamination is one of the major modes of failure for composite materials. VCCT is the study of damage based on the Energy Release rate of the material undergoing Delamination. Finite Element Model and Engineering analysis of various standard specimens such as DCB, ENF, SLB and MMB specimens have been carried out by using VCCT approach which covers Mode I, Mode II and Mixed mode (Mode I and II) Delamination. Method of modelling is predicted and validated for a DCB composite laminate specimen. This technique is inculcated in predicting the Delamination onset in flat composite laminate standard specimens as mentioned above. Various parametric studies on behaviour of delamination with different material properties, different crack lengths and ply orientation are also studied and their effect on Delamination behaviour is presented. Further the same approach has been applied to curved composite laminate and the behaviour of these laminates under Mode-I, Mode-II and Mixed Mode delamination has been studied.