Fracture of Composite Materials Under Compression Along Cracks

Abstract

The axisymmetrical problems of fracture of bodies with near-surface penny-shaped cracks and two parallel penny-shaped cracks under compressive loads directed along cracks are considered. In the situation examined the start of the process of material fracture is determined by the local loss of stability of the equilibrium of the material surrounding cracks. There are two approaches that are used to investigate such problems, namely, so-called “beam approximation” based on applied theories of mechanics of thin-walled structures and the approach in the framework of the rigorous three-dimensional linearized theory of stability of deformable bodies. According to the second approach we reduce the problems to systems of integral Fredholm equations and then to system of algebraic linear equations with use the Bubnov-Galerkin method and numerically analytic technique. As an example we present the numerical calculation for a composite material. The values of critical loads corresponding to the start of fracture are obtained for small and large distance between the cracks (or between the crack and the body surface).