Nonuniform shear strains in torsional Kolsky bar tests on soft specimens

摘要: Abstract : We investigate inertial effects in torsional Kolsky bar tests on nearly incompressible, soft materials. The results are relevant for materials with instantaneous elastic shear modulus the order of 1 1000 kPa and density water. Examples include brain tissue many other tissues surrogates. have conducted one- three-dimensional analyses simulations to understand stress strain states that exist these a test. demonstrate short loading pulses typically used high strain-rate (e.g., 700 = s) do not allow softer specimens ring-up uniform consequently versus data reported literature erroneous. also show normal components, which present even quasistatic torsion nonlinear materials, can be amplified dynamic widely study inelastic solids [Gray 2000; Chen Song 2011]. In compression test, relatively thin specimen is sandwiched between two bars. Impact at one end incident generates compressive wave travels along bar, through specimen, into transmission bar. goal this test subject uniaxial (biaxial) prescribed axial strain-rate. These conditions often achieved after an initial period involving multiple reflections from specimentransmission specimen-incident interfaces. Once been stress, strain, histories deduced gage measurements bars: proportional t