Perfect elastic-viscoplastic field at mode I dynamic propagating crack-tip  

作　　者：王振清 梁文彦 周博 苏娟 

机构地区：[1]School of Civil Engineering,Harbin Engineering University,Harbin 150001,P. R. China

出　　处：《Applied Mathematics and Mechanics(English Edition)》2007年第4期495-500,共6页应用数学和力学（英文版）

基　　金：Project supported by the Ph. D. Programs Foundation of Ministry of Education of China(No.20060217010)

摘　　要：The viscosity of material is considered at propagating crack-tip. Under the assumption that the artificial viscosity coefficient is in inverse proportion to power law of the plastic strain rate, an elastic-viscoplastic asymptotic analysis is carried out for moving crack-tip fields in power-hardening materials under plane-strain condition. A continuous solution is obtained containing no discontinuities. The variations of numerical solution are discussed for mode Ⅰ crack according to each parameter. It is shown that stress and strain both possess exponential singularity. The elasticity, plasticity and viscosity of material at crack-tip only can be matched reasonably under linear-hardening condition. And the tip field contains no elastic unloading zone for mode I crack. It approaches the limiting case, crack-tip is under ultra-viscose situation and energy accumulates, crack-tip begins to propagate under different compression situations.The viscosity of material is considered at propagating crack-tip. Under the assumption that the artificial viscosity coefficient is in inverse proportion to power law of the plastic strain rate, an elastic-viscoplastic asymptotic analysis is carried out for moving crack-tip fields in power-hardening materials under plane-strain condition. A continuous solution is obtained containing no discontinuities. The variations of numerical solution are discussed for mode Ⅰ crack according to each parameter. It is shown that stress and strain both possess exponential singularity. The elasticity, plasticity and viscosity of material at crack-tip only can be matched reasonably under linear-hardening condition. And the tip field contains no elastic unloading zone for mode I crack. It approaches the limiting case, crack-tip is under ultra-viscose situation and energy accumulates, crack-tip begins to propagate under different compression situations.

关 键 词：dynamic propagation elastic-viscoplastic material crack-tip field viscosity 

分 类 号：O346[理学—固体力学]