预蠕变──塑性的本构描述及其实验验证

Constitutive Description of Precreep-Plasticity with Experimental Verification

基于热力学相容的本构模型并合理地定义广义时间标度，得到了描述蠕变、塑性及其交互作用的统一型本构方程。进而通过对蠕变、塑性及其交互作用过程中材料内部子结构及其变化的分析，将材料的强化分解为对应于累积非弹性变形的强化和由蠕变变形导致的附加强化。对高温环境二维应力路径下３１６不锈钢的预蠕变－塑性变形过程进行了分析，取得了与Ｏｈａｓｈｉ等的实验数据相吻合的结果。

In this paper we put forword a constitutive model based on thermodynamics,Byintroducing generalized time scale, unified constitutive equation including descoription of creep,plasticity and the creep-plasticity interaction effects, is presented,It is shown that the present unifiedconstitutive equation includes plasticity as one special case(dt=0)and creep as the other one(ds=0).By means of analysis of material subetructure for creep, plasticity and creep-plasticityinteraction,a multiplicative harderung function analysis developed here has been compared with Ohashi'sexperimental results,It seem that the present theory could satisfactorily describe Ohashi'sexperimental results.