Tensor Transformations and Failure Criteria for the Analysis of Fiber Composite Materials

Abstract

Classical lamination theory for fiber composites is inherently limited to the 2-dimen sional conditions appropriate to thin shell configurations. A new derivation with ap propriate tensor transformations is given which provides a fully 3-dimensional lamination theory that is applicable to thick laminates involving "out-of-plane" stress terms. In con nection with this work a new failure criterion is derived for fiber composites, one which involves a minimum number of failure parameters, and offers insight into the modes of failure. The key to both derivations is the restriction of the five properties form of transversely isotropic media to a special form involving three independent properties. The reduced theoretical forms and the failure criterion are evaluated with respect to standard experimental data for fiber composites.