Axisymmetric sheet forming of knitted fabric composite by combined stretch forming and deep drawing

Abstract

Previous studies have demonstrated that sheet formability is governed by the interlacing effect of pure stretch forming and pure deep drawing. In this paper, knitted fabric reinforced thermoplastic composite sheets, which exhibit excellent stretchability and drapeability, are investigated for their formability. Initially a new parameter, X, which describes the amount of stretching relative to drawing during forming is introduced. It is shown that sheet forming processes, specified by the use of various combinations of forming conditions, can be characterized by the parameter X. Finally, the overall formability of knitted fabric composite sheet is discussed with reference to the X-factor.