弹性-应变软化粘塑性材料反平面剪切动态扩展裂纹尖端的渐近解*

本文首先给出了一种用于描述材料软化,并存在有粘塑性的材料模型.用这种模型对反平面剪切型动态扩展状态下,裂纹尖端的弹粘塑性场进行了渐近分析,给出了弹性－应变软化粘塑性材料反平面剪切动态扩展裂纹尖端的渐近解方程.分析结果表明,在裂纹尖端应变具有(ln(R/r))1/(n＋1)的奇异性,应力具有(ln(R/r))-n/(n＋1)的奇异性.从而本文揭示了应变软化粘塑性材料反平面剪切动态扩展裂纹尖端的渐近行为.

The Asymptotic Solution to the Antiplane Shear Dynamic Crack-Tip Field in an Elastic Strain-Softening Viscoplastic Material

The elastic strain softening-viscoplastic model is given in this paper. Using this model, the asymptotic stress and strain equations surrounding the tip of a propagating crack are given and numerical results are obtained under antiplane shear. The analysis and calculation show that at the crack tip the strain possesses logarithmic singularity(1n(R/r) )~1/(n 1)while the stress is like (1n(R/r) )~-n(n 1), therefore the asymptotic behaviour of the elastic strain-softening viscoplastic field is revealed under the antiplane shear.