韧性断裂准则的试验与理论研究.pdf

) ) ) 1, 2 1 1 虞 松 陈 军 阮雪榆 1. 上海交通大学国家模具CAD 工程研究中心, 上海, 200030 2. 山东大学, 济南, 250061 : 对不同样 的45 钢和6082铝合金试件进行了拉伸压缩剪切扭转等材料试验, 对工程中使用的 11 个韧性断裂准则进行对比研究,并利用专业塑性成形分析软件对试验过程 进行二维和三维情形的数值模拟指出目前使用的韧性断裂准则都不可能对材料在任意应力 应变状态和变形累积的情况下给出一个固定阈值,并给出了基于等效应变和应力三轴度的韧 性断裂准则修正公 ,通过厚板普通冲裁和精密冲裁试验证明了结论的有效性 :; ; ; ; :O346. 1;T G301 : 1004) 132X( 2006) 19) 2049) 04 Experimental and Theoretical Research on Ductile Fracture Criterion 1, 2 1 1 Yu Song Chen Jun uan Xueyu 1. National Die and Mold CAD Engineering esearch Center, Shanghai Jiao T ong University, Shanghai,200030 2.Shandong University, Jinan,250061 Abstract: T ension, compression, torsion and shearing test on 45 steel and aluminum alloy 6082 were utilized for providing the experimental values of the critical values at fracture, and 11 widely used ductilefracture criteriawere selected to simulate the physical experiments and their relative accu- racy for predicting and quantifying fracture initiation sites were investigated. The comparing results show that it is impossibleto capture all features of ductile fracture in different stress and strain states with a single criterion. A modified criterion based on effective strain and stress triaxiality was presen- ted. T he research results are checked experimentally using the blanking and fine blanking tests. Key words: ductile fracture criteria; metal forming process; material experiment; stress triaxiali- ty; blanking test 0 引言 , ,, ( 01 1m