Strength Criteria for Anisotropic Materials

Abstract

Light weight and high strength anisotropic composites like carbon/carbon, graphite epoxy, etc., under different combinations of applied stress components (biaxial and triaxial stress conditions) pose a challenge to designers for establishing reliable failure criterion. Stimulated stress components in composite turbine disk under the influence of centrifugal loads and air stream pressure is a typical example. In this article we propose to use fourth order tensor polynomial failure criterion for investigating the failure mechanisms in turbine disk. Fourth order polynomial strength criterion provides better approximation to experimental data than second order criterion, and also explains the nature of failure mechanisms of anisotropic materials.