In-plane Torsion Tests, Toward Large Strains Under Monotonic and Cyclic Loading of Sheet Metals

When compared to the simple shear test, the in-plane torsion test allows for large strains to be achieved without edge effects, specimen tearing from the jaws or buckling. The proposed device offers full optical access to the specimen and enables the use of 2D Digital Image Correlation. In this way, we can observe the effects of the material anisotropy on the strain all along the circumference of the specimen up to large strains. A series of radial grooves machined on the specimen’s inner clamped surface enables the transmission of large torques necessary for high-strength steels. The paper illustrates the potential of this test for the study of plasticity with a focus on anisotropy, large deformations, and cyclic testing. Two steel sheets are considered, a deep drawing low carbon steel DC01 and a stainless steel AISI304. The paper aims to establish a direct relation between Hills’ anisotropy model parameters identified from the standard uniaxial tests and the angular evolution of the effective strain along the shear gage section of the in-plane torsion specimen.