A Contribution to the Optimisation of a Simple Shear Test

Abstract

The finite element method is a widely used tool in sheet metal forming. The quality of the results of such an analysis depends largely on the applied constitutive model and its material parameters, which have to be determined experimentally. These data are relevant on the choice of the yield criterion among the wide range of options available in the commercial applications implementing the finite element method. Since the accuracy of material parameters estimation is therefore crucial, investigations were performed with an Al-Mg sheet alloy and a mild steel sheet to optimize a Miyauchi-based simple shear test. This method is one of the basic ways to investigate the plastic properties of a sheet metal up to large strains, which is very important for numerical analysis of sheet metal forming processes. Aim of the test is to determine the shear stress-strain correlation. In order to enhance the quality of the experimental results the detection of the deformation’s field, trough an optical measurement system, and the methodology for its evaluation are focus of the present study.

Novel Semi-Empirical Model for Forming Limit Prediction of Sheet Metal Material with Regard on Effects of Shear-Tension Loads

“…Thus, the analysis of resulting strain paths of major and minor strains of 15°-and 45°-specimen (15°-SP, 45°-SP) show a decreased formability compared to conventional FLC, as can be seen in Fig. 1 [6]. The only explanation of this fact is the influence of the superposed shear proportions, which lead to a decreased formability of considered material.…”

“…Experimental results in [6] have shown that formability of material changes by superposing shear loads to tension loads. These changes in material's formability cannot be explained by using conventional Forming Limit Curve.…”

“…For characterisation of bendability the "Bending Limit Curve" was defined [2]. For characterising material properties under shear loads Miyauchi proposed a simple test set-up [3], which was often used and optimized [4,5,6] for material characterisation. Additionally investigations on the influence of shear-tension loads on materials formability has be done by developing novel sample geometries or testing procedures [7,8].…”

“…Experimentally measured strain paths of novel shear specimen geometries (Material: DP600, 1.75mm)[6] …”