Characterization of sheet metals in shear over a wide range of strain rates

Abstract

A new specimen geometry, based on ASTM B831, for characterization of sheet metals in shear is introduced. The specimen can be tested in both quasi-static and dynamic tests using a load frame and a tensile split-Hopkinson bar (SHB) apparatus, respectively. Specimens with this new geometry and spool-shaped torsion specimens were fabricated from the same 0.5'' rolled 2024-T351 aluminum plate. Static and dynamic tests at strain rates up to 2,000 1/s on both samples were conducted using an axial-torsional servo-hydraulic load frame, a tension SHB, and a torsion SHB. Three-dimensional digital image correlation was used to directly measure deformation of the surface of the sample's gage section in both static and dynamic tests. Stress-strain curves obtained from tests with both types of specimens agree, indicating that the new sample geometry is suitable for the characterization of ductile sheet metals in shear. © The Society for Experimental Mechanics, Inc. 2014.