Validation of the Klepaczko-Malinowski model for friction correction and recommendations on Split Hopkinson Pressure Bar

The paper presents some aspects related to boundary conditions perturbing measurements during dynamic compression performed with a Split Hopkinson Pressure Bar (SHPB). The analyses are focused on the influence of such effects like friction, inertia, punching, elastic wave dispersion and contact zone shape between the input bar and the projectile on the estimation of dynamic material properties. Taking these experimental restrictions and influences into account allows for better understanding of the measurements used to define the thermoviscoplastic material behavior. The results of these tests together with presented numerical simulations enable for a better understanding of the phenomena and the reduction of errors which accompany the measurements in compression testing at low and high strain rates. (C) 2011 Elsevier B.V. All rights reserved.