High strain rate study of OFHC copper by experiments and simulations

Dynamic behavior of materials is generally dependent on the strain rate, so that a high strain rate test is used to study the behavior of materials in dynamic loads. Commonly used strain rate tests include Taylor Test, Hopkinson Test, Dynamic Tensile Testing, and Ballistic Testing. The strain rate in dynamic deformations is an important parameter in most of the material models such as Johnson-Cook which is used in many finite element software to simulate material behaviors. J-C model has 5 constants that are mainly determined through experiments, optimization and FE simulation. Selected material in this study are OFHC pure copper. Samples made of this materials were tested using high strain rate condition such as Tensile Hopkinson tests, Taylor, dynamic tensile extrusion (DTE) and ball impact. In the optimization stage the difference between the change of geometry in simulation results and dynamic experiments is considered as objective function. Finally, material constants are determined and validated by other test data.