压-剪混合型定常扩展裂纹尖端的弹黏塑性场

假定黏性系数与塑性等效应变率的幂次成反比，考虑其黏性和裂纹面摩擦接触效应 建立了压-剪混合型定常扩展裂纹尖端弹黏塑性场的渐近方程，求得了裂纹尖端场不含应力、应变间 断的数值解. 并讨论了压-剪混合型裂纹数值解随各个参数的变化规律，计算结果 和分析表明，压-剪混合型裂纹尖端场是满塑性的，不含有弹性卸载区，黏性效应是研究扩展裂纹尖端场时的一个重要因素. 无论混合裂纹趋近I型还是趋近II型，静水压力随摩擦系数的增加都是增加的,裂纹面摩擦 效应是阻止裂纹扩展速度的因素，且摩擦作用越强，裂纹尖端场的韧性越高.

The Elastic-viscoplastic Field At The Mixed-mode Steadily Propagating Crack-Tip Under Compression And Shear

Under the assumption that the artifical viscosity cofficient is in inverse proportion to power law of the plastic strain rate.The friction touch effection beween viscosity and crack-tip surface be considerde,the asymptotic solution is established for elastic-viscoplastic field at the mixed-mode propagating crack-tip under comprission and shear.The numerical solution to crack-tip without stress and stain gap is got. The variation of numerical solution are discussed for the mixed-mode under compression and shear according to each parameter.It is shown in numerical results and analysis that for the mixed-mode crack-tip field under compressing and shear is whole plastic without elatic unloaded section,viscosity effection is an important factor when propagating crack-tip field is studied, whether the mixed-mode crack trend to mode I or to mode II,the hydro-statil stresses are added according to the increasing on frictional coefficient. The crack-tip propagating velocity is prevented due to the frictoon on crack face,the tenacity on crack-tip freld become more higher with the more strorger on friction. Keywords: mixed-mode crack-tip under compression and shear; steadily propagating; viscosity effection elastic-viscoplastic materials