Determination of the 3D failure envelope of a composite based on a modified Arcan test device

This paper describes a 3D failure criterion identified through Arcan tests, to analyze the behavior of a laminate composite subjected to out-of-plane loadings. The proposed criterion is based on the Hashin's hypothesis and the interactions between tensile and shear out-of-plane loadings are taken into account. The out-of-plane stresses generated in the composite subjected to an Arcan test are studied using 3D Finite Element calculations in order to determine the stack sequence influence. Using different angles of the loading and different stacking sequences allows the ply to be subjected to complex 3D stress state. Using the experimental results and an inverse identification procedure, it is possible to identify the out-of-plane failure envelope. It is shown that a quadratic failure envelope, which takes into account a decrease of the apparent shear strength in the presence of out-of-plane tensile stress, permits the model to describe in a correct manner the experimental results.