Response of elastic solids to a moving discontinuity (Q581033)

The high frequency radiation from a nonuniformly moving discontinuity in an elastic solid is obtained. The discontinuity is modelled as a supersonic Somigliana screw dislocation and the analysis is made through use of the stationary phase method. Inversion of the dominant high frequency terms into the time domain gives the elastic motion at the shock-front and shear-front as well as an approximate closed form solution for all time. The dynamic displacement discontinuity of the dislocation is of the form \(\Delta u_ z=U(\xi)f[t-t_ R(\xi)]\). Simple forms of \(\Delta u_ z\) have been treated previously in the literature, so that this work also presents some comparisons with these earlier efforts.