考虑孔洞大小及分布非均匀性的材料细观损伤

为了研究金属材料中由于夹杂或第二相粒子的存在所形成的孔洞等 ,细观缺陷的大小及分布的非均匀性对材料损伤演化的影响 ,建立了孔洞群三维体胞模型 ,可以在孔洞大小及分布非均匀的情况下对材料损伤进行有限元模拟计算 .计算结果表明 :孔洞非均匀性增强了材料局部孔间干涉作用和孔洞的长大 ,引起材料损伤局部特性不均 ,因此 ,非均匀细观结构较均匀化假设更易于造成材料的损伤和破坏 ;采用常系数 q1和 q2 描述孔间干涉作用是不够准确的 ,q1及 q2 是逐渐增大的变化量

Study on the Evolution of the Meso-damage of the Metallic Material Containing the Voids of Heterogeneous Size and Distribution

There are voids in metallic material. They are formed because of inclusions and second-phase particles, and their size and distribution are generally heterogeneous. This paper is aimed at studying the influence of the heterogeneity of the size and distribution of the voids on the evolution of the meso-damage of the metallic material. For this purpose, a three-dimensional cell model is established, and the damage of the metal is calculated by finite element method. The calculated result shows that, the heterogeneity of the voids strengthens the interaction among them and accelerates the growth of them. It also results in the heterogeneity of the damage. Therefore, The heterogeneous voids have more serious damage to the metallic material than homogeneous ones. In additions, it is found that the parameters of q 1 and q 2 in Gurson's modified model are gradually increasing variables instead of constants in the process of the growth of the voids.