晶粒数量对多晶集合体初始各向异性的影响  

Effect of grain number on plastic anisotropy of random polycrystalline aggregates

作　　者：张光[1] 张克实[1] 冯露[2] 

机构地区：[1]西北工业大学工程力学系,陕西西安710072 [2]上海交通大学工程力学系,上海200240

出　　处：《计算力学学报》2004年第6期706-710,共5页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(50371070);航空科学基金(01C53015);西北工业大学博士论文创新基金资助项目.

摘　　要：Taylor类多晶晶体粘塑性模型被用于研究晶粒数量对随机分布多晶体拉伸塑性各向异性的影响。分别沿包含不同晶粒数量的多晶集合体的各方向进行单向拉伸数值模拟实验,得到多晶集合体各方向在一定等效应变下的等效应力,并用云图和等高线表示在多晶体的参考球面上。定义了描述多晶集合体各向异性程度的参考指标。讨论了三种确定晶体随机取向的方法。计算结果表明:晶粒数量有限的多晶集合体的应力应变响应仍有一定的各向异性,且随着晶粒数量增多,多晶集合体的各向异性程度降低;就所包含晶粒数相同的多晶集合体来说,在确定晶粒随机取向时,选取不同的方法对它的各向异性程度也有一定的影响。Taylor-type polycrystalline model is used to investigate the effect of grain number in random polycrystalline aggregates on its plastic anisotropy. Numerical tensile test is carried out to get effective stress under a given effective strain. In the simulation, aggregates of single crystal grains with different number of grains are used when loading along different directions. The stresses gained are denoted on the reference spherical surface. And a reference variable is defined to describe the degree of anisotropy. The results from simulation show that the stress-strain response predicted by the model with definite grain number displays some degree of anisotropy, but with the increase of the number of grains the degree of anisotropy simulated by the model is decreased. Even for the same number of grains when taking the different methods to determine the random orientation, the degree of anisotropy of simulated is different.

关 键 词：晶体塑性 初始各向异性 多晶体材料 

分 类 号：O344[理学—固体力学] TG113.25[理学—力学]