TRANSIENT CRACK-GROWTH IN A VISCOPLASTIC SOLID

Near-tip fields for transient crack growth in a material whose constit utive behavior is represented by the Bodner-Partom model are investiga ted for the case of plane strain mode I fracture under small-scale yie lding conditions. At time t = 0, a load is applied to the cracked body . At the same instant, the crack starts to propagate with a constant v elocity. A boundary integral equation method is used to compute the co mplete fields of stress and deformation. An expression for the near-ti p time-dependent stress intensity factor has been derived and numerica l results are presented for several crack tip speeds. Evolution of the stresses as the crack extends quasi-statically into the viscoplastic solid is also presented.