Design and conceptualization of a cutting tool to investigate the influence of the shear cutting process on edge crack sensitivity

Abstract

High-strength and ultra-high-strength sheet materials are becoming increasingly integrated in the automotive and commercial vehicle industries. Consequently, their edge crack sensitivity requires particular attention, starting with the component design. In addition to the only standardized testing method, the hole expansion test according to ISO 16630, various testing procedures characterize the occurrence of edge cracks. However, neither the ISO standard nor any other published experimental setup focuses on the design of the cutting tool used to generate the cutting surfaces, which is fundamental in order to produce conclusive results with low variance. This paper presents the constructive design and choice of materials with regard to a cutting tool for the Edge-Fracture-Tensile-Test as well as a punching tool for the hole expansion test. The modular concept allows an evaluation of the influence of the following parameters on the edge crack sensitivity: single-stage or multi-stage shear cutting process, open or closed cutting line, die clearance, cutting edge geometry.