A three-dimensional micro-mechanical model for predicting the layer longitudinal compression strength of composite laminates

A three-dimensional micro-mechanical model for predicting the compressive strength of composite laminates is presented in this paper. The effect of initial misalignment of fiber angle on the compressive strength of fibrous composites is investigated. The compressive strength of fibrous composites is estimated using the actual initial misalignment of fibers in the rotated plane. The initial misalignment angles in both directions are defined as a curve in the form of a cosine function. Equilibrium equations are then derived for a Representative Volume Element (RVE) along the axis of the fibers using total potential energy principle. Minimization of the total potential energy with respect to the amplitudes defined by the initial waviness function of the fibers yields a formula used to define the maximum compressive strength of fibrous composite materials. The formula obtained in this paper is used to study continuous fiber/polymer matrix composites. The results obtained by the model presented in this paper are in a good agreement with experimental data obtained from compression tests on [±60°/0°] specimens and theoretical results available in the literature.