Application of a non - local criterion to fracture prediction in plane – strain drawing

Abstract

A popular method for fracture prediction in metal forming processes is based of the concept of workability diagram. However, for some constitutive models direct applications of this method are impossible when fracture occurs at maximum friction surfaces because the velocity field is singular such that the equivalent strain rate approaches infinity at such surfaces. To overcome this difficulty, it is possible to adopt non – local fracture criteria which can also be based on the workability diagram. In the present paper such a criterion is used to predict fracture in plane – strain drawing.