An experimental diffraction grating study of the quasi-static hypothesis of the split hopkinson bar experiment

Abstract The determination of approximate dynamic stress-strain data from the split Hopkinson bar experiment requires that one make the theoretical assumption in advance that the uniform stress and strain distributions of quasi-static measurements apply during impact. Direct diffraction grating measurement of strain along the short bar specimens are described in this paper. Observed non-uniform finite strain distributions and observed nonlinear wave initiation, propagation, reflection, and interaction phenomena provide direct experimental evidence of the non-applicability of the quasi-static hypothesis in such ‘extended quasi-static’ impact tests.