抄録
An elastodynamic boundary element analysis of a fast crack propagation test is performed. A propagating crack subject to a time-dependent uniform pressure on its surfaces is considered. The crack speed is determined in such a way that the dynamic stress intensity factor K1(t, v) is equal to the fast crack propagation toughness KID. Caustics in reflection are generated by making the assumption of plane stress. The time variation of the "measured" KID is obtained from the diameter of the generated caustics. The KID thus obtained is found to depend on crack propagation history due to the transient nature of the elastic stress field near a propagating crack tip. This may explain to some extent the physical meaning of the experimental data showing the dependence of KID on crack acceleration.
