Semi – automatic approach for the creation of non - proportional load paths

Abstract

Abstract Many industrial sheet metal parts experience a non – proportional loading history. The determination of such non – proportional loading paths on a laboratory scale is still very challenging and time - consuming. Most tests require different machines, tools and measurement techniques. Norz and Volk [1] have presented a new approach to create arbitrary non – proportional loading paths by using a cruciform specimen in combination with a draw bead tool. This simple experimental setup lead to a significant reduction in the experimental effort. It allows the generation of arbitrary loading paths by using only one machine, one tool and one specimen geometry without any further processing of the specimen between the forming steps. Nevertheless, the strain path could only be controlled manually after a certain forming step. In this paper, an in-line strain measurement was used to observe the real – time strain path during the experiment. This information was used to create a semi-automatic approach in which the draw bead height is adapted in order to create a prescribed strain path.