Dynamic Tensile Failure of Glycerol

Abstract

A tensile strain was induced in shock-loaded glycerol by the intersection of two rarefaction waves, one of which was caused by the partial reflection of a shock from an interface with octane, a material of lower shock impedance. The maximum tensile stress and the subsequent tensile stress relaxation due to void nucleation and growth were measured indirectly by a stress gauge placed in the octance. The dynamic tensile strength of the glycerol was measured to be ≈ 0.25 kbar for an initial tensile stress rate on the order of 107 kbar/sec. Calculations indicated that spherical voids in glycerol of between 0.01 and 10 μ in radius follow a viscous growth law under tensile strain, and computations using this growth law showed the influence of fractional void volume and strain rate upon the macroscopic stress history during cavitation. Several possible void nucleation mechanisms are discussed.