Classical laminate theory model for twill weave fabric composites

The present paper is concerned with the development of an analytical model, based on Classical Lamination Theory, to predict the stiffness of twill in composites. A very simple yet quite general model is developed to obtain the elastic properties, i.e. extensional stiffness (A), extension-bending coupling stiffness (B) and bending stiffness (D). The model takes into account effects of the fabric structure by considering tow undulations and continuity along both the fill and warp directions. Various tow cross sections are possible and can be easily incorporated for a particular application. The model results in simple formulae for calculating in-plane and bending elastic constants, which can be used fur-ther in structural analysis. (C) 2001 Published by Elsevier Science Ltd.