反平面剪切动态扩展裂纹尖端的弹-粘塑性场

采用Bingham弹性-粘塑性模型对反平面剪切动态扩展裂纹尖端的应力应变场进行了渐近分析．给出了适当的位移模式、推导了渐近方程并且给出了数值解．分析和计算表明对于低粘性情况，裂纹尖端场具有对数奇异性．对于高粘性情况，裂纹尖场具有幂奇异性A·D2对于临界情况，两种奇异性可以相互转换．揭示了粘性在裂纹尖端场研究中的重要作用．

Elastic-Viscoplastic Fieds Near The Tip of a Propagating Crack Under Anti-Plane Shear

The elastic-viscoplastic model proposed by Bingham was used to alalyse the stress and strain surrounding the tip of a propagating crack under antiplane shear.The proper displacement pattern was given;the asymptotic equations were derived and solved numerically.The analysis and calculation show that for smaller viscosity the crack-tip possesses logarthmic singularity,and for larger viscosity it possesses power-law singularity.In critical case,the two kinds of singularity are consistent with each other.The result revealed the important role of viscosity for crack-tip field.