Delamination Damage Analyses of Lap Shear Joints Made with Flat Fibre-Reinforced Polymer Composite Laminates Subjected to Transverse Load

In this work, initiation and growth of pre-embedded delamination in the adhesive-bonded lap shear joint (LSJ) made out of laminated fibre-reinforced polymer (FRP) considering flat geometry subjected to transverse load have been investigated. 3D nonlinear finite element technique has been employed to monitor the damage mechanism. The critical location to place the delamination has been obtained from the Tsai-Wu failure criterion. It is found to occur between the first and second layers of the bottom adherend of the Lap shear joint. Proper contact elements have been employed to avoid any interpenetration of delaminated surfaces. Interlaminar peel and shear stresses are obtained and found to be three dimensional in behavior. Virtual crack closure technique (VCCT) is used to determine the three components of strain energy release rates (SERR) with respect to sliding (Mode I), opening (Mode II) and cross sliding (Mode III) modes of failure. These values are found to be different along two delamination fronts which show the dissimilar nature of propagation of delamination.