【摘要】 研究了应变损伤材料Ｉ型动态扩展的裂纹尖端场。假定材料服从Ｊ＿２流动理论，且损伤规律以幂律应变软化的规律给出。对于塑性区引进了应力函数φ，ψ。借助于动力学方程的分析，给出了渐近方程及数值解。结果表明，对于可压缩材料Ｉ型平面应变尖端场是完全由塑性区组成，没有弹性卸载区。在裂纹尖端附近，应力和应变分别具有如下的奇异性：更多还原

【Abstract】 In this paper the mode I dynamic crack-tip field propagating in a strain-damage material is stud-ied The mediam is assumed to obey the J₁ flow theory and the damage rule is given asymptotically ina form like power-lawe strain softening. Two stress functions φ,ψ are introduced for plastic domain.By means of dynamic equations, the asymptotic equations are given and sofved numerically. The re-sults show that for general compressible materials , the mede I plane strain crack-tip field is fully plas-tic, there is no unloading elastic region. At the crack tip the strain possesses the logarithmic singularity（ln）, while the stress is like（ln）更多还原