CRACK-TIP ASYMPTOTIC CHARACTER OF ANTIPLANE STRESS AND STRAIN-RATE FOR LINEAR FRACTIONAL CONSTITUTIVE RELATIONS

Linear-fractional strain rate and stress relations are used to simulat e materials undergoing steady slate creep. The crack tip asymptotic ch aracter of the stress and strain rate field is obtained in exact and a pproximate form. In the limit as the radial distance emanating from th e crack tip approaches zero, the stress field corresponds to that for an ideal plastic material while the exact and approximate solutions te nd to coincide. Discussed is the nonhomogeneous singular character of the strain rate field that possess different orders of singularities i n a circular region around the crack tip.