Representation of Local Stiffness Variation in Textile Composites

Abstract

The high degree of heterogeneity in fabric composite materials is identified as a major problem in their structural analysis. A procedure is proposed to represent the material stiffness variation as a function of the spatial coordinates by using splines. The stiffness variations are exemplified using a plain weave composite. The role of this stiffness function is to facilitate the calculation of the averaged material stiffness tensor for arbitrary domains in the form of finite elements. Once this exercise has been completed for a meshed part, a finite element analysis can be performed in order to obtain information on a local level. The facility with which the averaged material stiffness tensor over an element can be calculated is not only important in terms of underpinning mesh refinement and adaptive meshing, but, more importantly, to conduct a more correct and precise, i.e. material adaptive, stress analysis.