High Strain Rate and Plastic Deformation Response of OFHC Copper by Finite Element Method

Finite element simulations of pressure-shear plate impact experiment are conducted to investigate the plastic behaviour of OFHC copper under high strain rate loadings. OFHC copper is sandwiched between two harder plates which possess enough strength to remain elastic under high velocity impact. Two methods are implemented to achieve shear flow stress and shear strain in the OFHC copper: (1) measuring transverse velocity in free end of target, and (2) choosing an element in center of the sample and directly calculating shear stress and shear strain. Good agreements are found between two methods and published experimental works. After validating the finite element model with the former published experimental results, the effective parameters, such as initial flyer velocity, tilt angle, and material properties of flyer and plates, are studied. Also, the critical flyer velocity and tilt angle to use from theory of pressure-shear plate impact experiment are evaluated.