Authors: G Subhash J Kwon R Mei D F Moore
Publish Date: 2011/06/14
Volume: 52, Issue: 6, Pages: 551-560
Abstract
A coordinated modeling and experimental effort to investigate the shear stressshear strain rate response of ballistic gelatin is presented A powerlaw constitutive model that captures nonNewtonian shearthickening behavior the evolution of viscosity and the momentum diffusion at high shear rates is adopted A simple asymptotic relationship between the maximum wall shear stress and the maximum striking wall velocity is derived in the high diffusion rate regime for a shear flow between two parallel plates Experimental investigation is conducted on double lapshear test fixture with gelatin specimens of different thicknesses subjected to high strain rate input on the inner surface generated by a polymer split Hopkinson pressure bar This test fixture allows measurement of transmitted shear stress as well as visualization of momentum diffusion through gelatin when imaged by a high speed camera Gelatin specimens of various thicknesses were used for extracting the powerlaw model parameters It is found that ballistic gelatin behaves as a shearthickening fluid at high shear rates with a powerlaw exponent of 222
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