Theory of Caustics for Mode-III Unsteadily Fast Propagating Cracks

摘要

In a previous study, the authors have derived the asymptotic solutions for the displacement and stress fields of unsteadily fast propagating cracks under mode III condition. In this paper, using the explicit expression for the asymptotic field, theoretical analysis is carried out for the method of caustics for unsteadily fast propagating cracks under the mode III. This theoretical analysis reveals the unsteady effects of dynamic crack propagation on the caustic patterns. The relation between the stress intensity factor and the size of caustic pattern is derived by the present analysis.