Draping of woven fabrics: Progressive drape model

This paper proposes a new membrane stress based model to predict the draping of woven fabrics over irregular surfaces. It has been well established that pure shear is the main mechanism allowing a woven fabric to conform to double curvature shapes. Although the kinematic drape models developed on this principle serve as good 'first order' approximations, they lack completeness since they do not account for fabric stiffness and processing conditions. At the other extremes are the comprehensive FE based drape models that account for the interaction of the fabric with the tool and the processing environment. Such models are computationally expensive and sensitive to the input parameters, some of which are difficult to measure accurately. The progressive drape model proposed in this paper takes an intermediate approach to the above two extremes. The paper presents the outlines of several approaches to developing a comprehensive model and illustrates the same by applying them to an in plane specimen, a hemisphere, and a helicopter pilot helmet. The outline of an intermediate model of a progressive form is then introduced along with a prototype implementation of the same. (C) 2003 IoM Communications Ltd.