FeCrNi合金静动态物理本构模型研究  

THE CONSTITUTIVE MODEL OF FECRNI ALLOY SUBJECTED TO STATIC AND DYNAMIC LOADING

作　　者：潘晓霞[1] 余勇[1] 谭云[1] 陈裕泽[1] 

机构地区：[1]中国工程物理研究院总体工程研究所,绵阳621900

出　　处：《力学学报》2008年第3期407-412,共6页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(10232040)~~

摘　　要：以金属材料塑性变形的位错动力学为基础,将FeCrNi合金的流动应力分解为非热应力和热激活应力两部分.通过对该合金屈服应力随温度变化特性、屈服应力的应变速率特性、孪晶组织的温度特性及位错组态的应变速率特性进行分析,认为非热应力不只是应变的函数,还与温度和应变速率相关,因此对Johnson-Cook模型方程形式进行修正以描述非热应力.同时认为影响热激活应力的微结构参数主要为位错阻碍间距△l,定义并推导出表征△l演化的g函数的表达式,将其引入Kocks的热激活方程,从而建立FeCrNi合金的物理型本构模型.该模型初步实现了对FeCrNi合金从室温到高温、从准静态到动态塑性变形行为的描述.In the present work, the flow stress of FeCrNi alloy is divided into two parts, athermal stress （longrange） and thermally activated stress （short-range）, based on the dislocation dynamics of plastic deformation of metal material. Firstly, the yield stress, twins and dislocation configurations of the alloy are analyzed with the effect of temperature and strain rate. Hence, modified Johnson-Cook model is introduced to describe the athermal stress. Secondly, the distance between dislocation barriers △l was found to mainly affect the thermally activated stress and the g（γ,γ, T） function was educed and input in the Kocks model. Therefore the constitutive model of FeCrNi alloy was developed to describe the plastic response of FeCrNi alloy from low temperature to high temperature, and from static loading to dynamic loading.

关 键 词：FeCrNi合金 非热应力 热激活应力 位错动力学 位错阻碍间距 物理型本构模型 

分 类 号：O344.4[理学—固体力学]