Structure analysis of mode IE quasi-static propagating crack tip field in creeping materials

A elastic-viscoplastic mechanics model was adopted to investigate asymptotically the mode HI quasi-static propagating crack tip field in creeping materials. The stress and strain fields at crack tip possess the same power law singularity under linear-hardening condition. And the singularity exponent is uniquely determined by the viscosity coefficient of the material. The numerical calculation results indicate that the hardening coefficient dominates the structure of crack-tip field but the secondary plastic zone has little influence on the field. The viscosity of the material dominates the strength of stress and strain fields at crack tip while it has certain influence on crack-tip field structure. The crack-tip field degenerates into the viscoelastic-perfectly-plastic one when the hardening coefficient becomes zero.