Respoflses of a cracked half-space subjected to an antiplane impact

摘要

The responses of a cracked half-space subjected to an antiplane shear impact on the surface of the half-space are investigated in time as well as in frequency domains. Both surface--breaking and sub-surface cracks are considered. The problem in frequency domain is solved by a combined boundary integral and finite element approach. The finite element method is used for the near- field, while the boundary integral representation is used for the far- field. The response in time domain is calculated by using fast Four- ier transform. The surface displacements, crack opening displace- ments and dynamic stress intensity factors are presented to show the significant effects of the cracks. The interaction of the impact waves and the crack can be clearly observed and understood from the numerical results in this paper. Some spectral amplitudes dis- play regular peaks which indicate the existence of resonance phenomena that are associated with the characteristics of the crack. The location, length and depth of the crack can be easily detected by means of surface responses.