摘要
为了研究粘性效应作用下的动态扩展裂纹尖端渐近场,建立了粘弹性材料动态扩展裂纹的力学模型.在稳态蠕变阶段,弹性变形和粘性变形同时在裂纹尖端场中占主导地位,应力和应变具有相同的奇异量级,即(σ,ε)∝r-1/(n-1).通过渐近分析求得了裂纹尖端应力、应变和位移分离变量形式的渐近控制方程;采用靶法求得了Ⅰ型Ⅱ型动态扩展裂纹尖端的应力、应变的数值解.数值计算表明:裂尖场变化主要受材料的蠕变指数和马赫数的控制.通过对裂纹尖端场的渐近分析,为动态扩展裂纹的断裂判据提供参考依据.
A mechanical model of a visco-elastic material was established in order to investigate the asymptotic field of a dynamically growing crack-tip in a viscous environment. It was shown that, in the stable creep growing phase, elastic deformation and viscous deformation are equally dominant in the near-tip field, and stress and strain have the same singularity level, namely, （σ,ε）∝ r^-1（n-1）. The asymptotic governing equation with separate variables for stress, strain and displacement in a crack-tip field was obtained by asymptotic analysis. The numerical solutions for stress and strain in a crack-tip field of mode Ⅰ and mode Ⅱ were obtained by the shooting method. Numerical calculation indicates that the near-tip fields are mainly governed by the creep exponent and Mach number. This asymptotic analysis provides helpful references for fracture analysis of dynamically growing cracks.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2007年第10期1089-1094,共6页
Journal of Harbin Engineering University
基金
黑龙江省自然科学基金资助项目(A20004-08)
哈尔滨工程大学基础研究基金资助项目(HEUF04005)
