Modeling of compressive failure in fiber reinforced composites

Abstract

The classical results of compressive strength in fiber reinforced composites are briefly reviewed. The microbuckling analysis by Rosen (1965) and the Argon-Budiansky analysis for kink band formation ( Argon, 1972; Budiansky 1983) are discussed and their results are rederived by using a new generalized Timoshenko beam model which is developed for a two-dimensional periodic matrix–fiber–matrix laminate. Introducing a ‘shear hinge’ to simulate a kink band and using the method of split rigidities it is shown that not only an initial fiber misalignment but also any misalignment in the loading system can affect the critical stress for kinking. A new mechanism based on shear instability of matrix is proposed for kink band formation and a simple formula is then derived to predict the kink band angle. Finally, a criterion for matrix yielding combining axial compressive stress and transverse shear perturbation is applied to modify the Argon–Budiansky kinking formula.