Failure analysis of notched fiber reinforced polymer composites under combined loading

A modified Arcan fixture was used in this paper to study the damage of notched fiber reinforced compo-sites under complex loading.Notched carbon-fiber reinforced composite specimens([-45/90/45/0]_s) were tested under combined tension and shear loading by stretching along 30°direction.The development of cracking in the surface ply of the laminates was measured by the digital image correlation method (DICM), and obvious splitting phenomena is observed at the notch tips. Afterwards a 3D laminate model was developed by finite element software ABAQUS. To capture the true stress concentration at the notch tips, cohesive contact zones were introduced in the model to simulate the splitting in each ply.In order to clarify the effect of rotational degree of freedom at the loading ends on the failure mechanisms and strengths of the laminates, two different boundary conditions were studied, i.e. constraining or relaxing the rotational degree of freedom.The result shows that the direction of resultant force dominates the failure mechanisms and strengths of the laminates. The simulation results with relaxed rotational degree of freedom are in good agreement with the experiments.