Evaluation of Various Approximate Analyses for Plain Weave Composites

Abstract

The literature contains a variety of analyses for analyzing plain weave composites. These differ in both geometric approximation and assumptions about stress and strain distribution. Herein the weave geometry for a wide range of waviness was described using three-dimensional finite element meshes. These meshes were used with various stress and strain assumptions to determine how these assumptions affect predicted in-plane extensional stiffness. Assumptions about stress and strain can be tied to whether an analysis is equivalent to a virtual work, complementary virtual work, or hybrid formulation. Since these variational principles have well understood convergence behavior, it is easy to explain the observed effects of the various assumptions. The results indicate that sometimes accurate predictions for particular cases result from cancellation of errors, rather than sound formulation.