A reconciliation of dynamic crack velocity and Rayleigh wave speed in isotropic brittle solids

摘要: Following earlier observations of multiple micro-crack formation accompanying crack propagation under dynamic conditions, the question regarding discrepancy between ‘theoretically anticipated’ maximal (Rayleigh wave) speed and those observed typically in amorphous, isotropic solids is examined experimentally. It shown that if production these micro-cracks ahead main fracture suppressed by fabricating a material possessing thin uniform region vanishing intrinsic (molecular/atomic) strength, materially increased to point approaching Rayleigh wave speed. Moreover, it also presence small discreet flaws sufficient spatial density similarly ‘weakens’ produce speeds comparable One deduces, therefore, for single front linearized theory elastodynamics correctly predicts behavior solid with sufficiently low strength.