ANTIPLANE DYNAMIC CRACK-PROPAGATION IN A VISCOELASTIC STRIP

A model of a uniformly moving semi-infinite crack in a linear viscoelastic strip subjected to antiplane loading is considered. For steady subsonic crack speeds, a rather general formulation of the problem is presented. Integral transforms are used to reduce the problem to one of solving a Wiener-Hopf equation. In contrast to the elastic case, the energy release rate of brittle fracture is a function of crack speed. The formal factorization of the Wiener-Hopf equation is performed numerically. Specific numerical results for the variation of the stress intensity factor with crack speed are presented for the three-parameter viscoelastic solid. Variations in the disparity of the long- and short-time moduli are found to have a greater effect on the stress intensity factor than changes of several decades in the relaxation-time. Comparison with previously obtained asymptotic solutions is made. © 1979.