Woven fabric composites: Developments in engineering bounds, homogenization and applications

First, methods are described for approximating upper and lower bounds for the elastic stiffness tensor for general woven fabric composites. Well accepted minimum energy principles are briefly presented to establish the foundation for practical finite element procedures for determining these bounds. Secondly, comparisons of four common homogenization procedures are shown: the strain energy balance method, the plate approximation method, a direct approach via area averaging, and asymptotic expansion. The boundary conditions are applied so as to obtain the well known Rule of Mixtures for a unidirectional uniaxial specimen. In attempting to consolidate much of the existing knowledge of structural constitutive models for WFCs, this research seeks to summarize and compare various homogenization methods via finite element analyses. And third, some illustrative applications are presented.