The strength of fibre reinforced polymer under a complex loading

Abstract

This article presents a model, known as generalized Daniels’ model, describing the process of micro-damage accumulation, deformation and failure of multilayered fibre reinforced composite structures under complex internal states of stress responding to external plane-stress loading. The model considers three independent kinds of ply micro-damage: longitudinal, transverse and shear. Non-linear analysis, taking into account scissoring effects, is used to make theoretical predictions for all the 13 test cases involved in the third world-wide failure exercise. The cases cover the biaxial failure behaviour of a unidirectional and multi-directional laminates, failure of thick and thin cross ply and quasi-isotropic laminates under tension, damage due to thermal loading, bending of a general laminate, loading and re-loading and the predictions of the tensile and compressive strength values of test specimens with an open hole. For the prediction of notched strength of laminates with hole, the model is used with a non-local approach based on the specific size of ply microstructure and Neuber’s hyperbola of specific deformation energy. The results are presented for all the 13 test cases.