FINITE ELEMENT ANALYSIS BY USING COHESIVE INTERFACE ELEMENT IN DOUBLE CANTILEVER BEAM

Delamination is a phenomenon of degradation of composite laminates that may lead structures to failure or that may reduce their stiffness and strength. Finite element analysis using the Cohesive Zone Method (CZM) is a widely used method for analyzing delamination in laminated composites. The aim of this thesis is to examine the effect of DCB geometry and mesh size on the delamination length of the cohesive material and to present the numerical model closest to the our experimental result. In order to eliminate the convergence problem of the mesh size, which is the main factor for the estimation of the process length, we prefer explicit analysis instead of implicit analysis. DCB was modeled according to Time Step Significance and Courant-Friedrichs-Lewy (CFL) characteristic length by Explicit time integration (central difference scheme). It has been seen that the factor close to the test result is with the height change of the material and it gives a better result than the mesh size change of the material.