Complementary techniques are used to investigate the dynamic loading of subsurface cracks in either homogeneous or non-homogeneous media; the quantities of interest such as the scattered fields and the stress intensity factors are determined. For homogeneous media these involve solutions utilising transform methods and the Wiener--Hopf technique. To ease interpretation an iterative method based on physical considerations is developed. For special loadings invariant integrals are utilised to provide non-trivial extensions of the analysis to non-homogeneous media, at least insofar as the stress intensity factors are concerned.
Co-authored with Duncan Williams.