Analysis of Delamination Damage and Eigenvalue Buckling of Lap Joint in CFRP Laminates Using Finite Element Method

Delamination damage is a characteristic damage which is observed in composite laminates. Delamination damage can be very disastrous, hence delamination analysis for any CFRP structure is necessary. In this paper epoxy carbon woven (230 GPa) Prepreg laminates was used as the adherend and FM-300K was used as adhesive to form a lap shear joint. The model was created using ANSYS ACP and analysis of delamination damage was done using 3D non-linear finite element method. Longitudinal buckling load was applied to study the eigenvalue buckling and deformation in different modes. Adhesive bonded lap shear joint made of fibre reinforced polymer (FRP) considering flat geometry subjected to longitudinal load has been investigated. The results were obtained for 10 modes in this analysis. Interpretation of the results shows that deformation decreases with increase in modes. It was also inferred that deformation is much smaller in modes where buckling occurs in two planes. Tsai-Wu failure criterion was used to observe the failure layers in the composite laminate structure. Crack Closure Technique was used to find out the strain energy release rates. It was observed that peel stress and shear stress in the inter laminar region was three dimensional in nature.