Compact forced simple shear specimen: Design improvement based on quasi-static experiments and finite element simulations

Abstract

Determination of the large-strain shear response of materials is important for an improved understanding of shear driven failure mechanisms as well as constitutive modeling efforts. While many shear specimen designs have been proposed in the literature, few systematic studies have examined the effects of varying sample geometry on the homogeneity of the resultant stress state and strain path. Here we propose modifications to the compact forced simple shear specimen of Gray et al. (2016), and use both digital image correlation and finite element analysis to determine the effect of specimen geometry on simple shear deformation at quasi-static rates in high purity wrought tantalum. For the specimens considered here, where a notch is used to create the shear zone, it is found that a notch inclination angle of 45 degrees provides a substantial improvement in the deformation behavior compared to a horizontally oriented notch. A parametric study of notch inclination angle is conducted using FEA simulation.