Optimization of the formability of knitted fabric composite sheet by means of combined deep drawing and stretch forming

Abstract

The formability of sheet metals has been investigated widely in the last 5 decades. However, formability studies on polymer composite materials are very limited and relatively new. This paper describes the sheet formability of knitted Kevlar fiber reinforced polypropylene composite material. Previous studies have indicated that sheet formability is governed by the complex interplay between pure stretch forming and pure deep drawing. For this purpose, a new parameter, X, which describes the amount of stretching relative to drawing during forming has been introduced. The formability characteristics of knitted fabric composite are discussed with reference to X. The effects of forming conditions (such as blank-holding load, the blank size and the tool geometry) on the composite formability are also described.