Free vibration analysis of orthogonal-woven fabric composites

Abstract This paper presents a study on the free vibration analysis of orthogonal-woven fabric composites. The fabrics are composed of two sets of mutually orthogonal yarns of either the same material (nonhybrid fabrics) or different materials (hybrid fabrics). We focus on the repeating unit of the woven structure, known as a `unit cell'. Based upon the one-dimensional (1D) elasto-dynamic analysis developed by the authors for such a woven fabric composite, the free vibration problem is formulated and solved for four basic boundary conditions. Natural frequency equations and natural modes are obtained analytically. For the special case of two bonded isotropic layers, closed-form solutions of natural frequencies and natural modes are given. It has been shown that numerical solutions can readily be carried out for woven fabric composites with arbitrary combinations of material and geometrical parameters. As an example, the first ten natural frequencies for plain weave composites based upon graphite/epoxy and glass/polyester are presented and discussed.