延性材料动态拉伸断裂早期连通过程的逾渗描述  

Percolation Description for the Early Stage of Void Coalescence during Dynamic Tensile Fracture in Ductile Materials

作　　者：王永刚[1] 贺红亮[1] 王礼立[2] 经福谦[1] 

机构地区：[1]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理实验室,四川绵阳621900 [2]宁波大学工学院力学与材料研究中心,浙江宁波315211

出　　处：《高压物理学报》2006年第2期127-132,共6页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金NSAF项目(10476027)

摘　　要：借鉴逾渗理论,提出了新的应力松弛函数,简称PR函数(Percolation-Release Func-tion),用以描述断裂发生前由于微孔洞连通而引起的快速应力松弛过程,具有较为明确的物理意义。通过其与损伤度函数模型进行耦合,对无氧铜和45钢平板撞击层裂进行了数值模拟。结果表明:数值计算不仅有效地再现了界面的应力历史和自由面速度历史,而且再现了靶中的损伤分布;新的逾渗松弛函数具有较好的适用性。Based on the frame of percolation theory,a new stress release function named as Percolation Release （PR） function has been proposed to describe the course of stress release during the early stage of void coalescence until the final or catastrophic fracture occurring. A clearly physical meaning is given for Dc0, the critical damage for the initiation of void coalescence, and Dr, the fracture critical damage. Coupled with damage function model proposed previously,PR function is applied to simulate the spall behaviors of OFHC copper and 45 steel as examples. Compared with the experimental measurements,numerical results indicate that the calculated stress profile and free surface velocity profile as well as the damage distribution in the materials being studied are consistent well with the experiments,and PR function has a good ability for describing the stress release just before the catastrophic fracture occurs.

关 键 词：逾渗理论 应力松弛 损伤演化 拉伸断裂 

分 类 号：O346.5[理学—固体力学]