Post-buckling failure studies on quasi-isotropic CFRP panels under positive and negative in-plane shear loading

Abstract

The shear buckling performance of a flat laminated composite structure depends on various factors like the nature of the applied load, lamina orthotropy, stacking sequence and the support boundary conditions. The emphasis of the current work is to decipher the effect of the direction of applied shear on the post-buckling response and failure of a quasi-isotropic carbon CFRP panel. A comprehensive experimental test campaign involving 3D-digital image correlation (DIC), acoustic emission (AE) and strain gaging techniques are used to capture the post-buckling deformation and the associated failure mechanisms in the CFRP test panels under positive and negative shear load. Further, a generic finite element based progressive damage model involving 3D Hashin’s failure criteria in conjunction with the cohesive zone model is developed in Abaqus software for simulating the intra and inter-laminar damages in the quasi-isotropic laminate and later compared with the experimental results. The effect of positive and negative shear on the post-buckling response and the associated damage modes are investigated in detail. The outcome of the current investigations reveals that the direction of the shear load has a definite impact on the post-buckling response and failure behavior of the CFRP test panels.