SCATTERING OF ANTIPLANE IMPACT WAVES BY CRACKS IN A LAYERED ELASTIC SOLID

The scattering of antiplane impact waves by cracks in a layered elasti c solid is investigated by using a hybrid method which combines the fi nite element discretization of the near field with the boundary integr al representation of the far field outside a contour completely enclos ing the crack. This combined method leads to a set of linear unsymmetr ic complex equations which are stored in a compacted data structure an d solved to obtain response spectrum by biconjugate gradient methods. The transient response is then obtained by FFT. Numerical results are presented for the surface displacements, crack opening displacements, and stress intensity factors to show the effects of the crack and the interface. Moreover, the propagation of reflected, diffracted, and dir ect impact waves can be clearly observed. (C) 1998 Elsevier Science S. A.