AN ANALYSIS OF DUCTILE RUPTURE IN NOTCHED BARS
AN ANALYSIS OF DUCTILE RUPTURE IN NOTCHED BARS
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DOI：
10.1016/0022-5096(84)90031-0
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发表时间：
1984-01-01
影响因子：
5.3
通讯作者：
TVERGAARD, V
中科院分区：
文献类型：
--
作者：
NEEDLEMAN, A;TVERGAARD, V
基于一组考虑微孔形核和长大的弹塑性本构关系，对轴对称和平面应变缺口拉伸试样的延性断裂进行了数值分析。最终材料失效的空隙合并纳入本构模型通过依赖的屈服函数上的空隙体积分数。在分析中，材料最初没有空隙，但随着空隙的成核和生长，宏观塑性流动的合成粘性和压力敏感性显着影响的解决方案。在计算中同时考虑钝切口几何形状和锐切口几何形状，可以研究高应变和高三轴度对失效的相对作用。与已发表的高强度钢缺口拉伸试样的实验结果进行了比较。所有轴对称试样分析失败的缺口截面的中心，而在表面的失败开始被发现在平面应变试样与尖锐的缺口，与实验一致。不同试样的结果被用来调查的情况下，断裂起始可以表示为一个单一的故障轨迹的应力三轴度与有效塑性应变的图。
Ductilefracture in axisymmetric and plane strain notched tensile specimens is analyzed numerically, based on a set of elastic-plastic constitutive relations that account for the nucleation and growth of microvoids. Final material failure by void coalescence is incorporated into the constitutive model via the dependence of the yield function on the void volume fraction. In the analyses the material has no voids initially; but as the voids nucleate and grow, the resultant dilatancy and pressure sensitivity of the macroscopic plastic flow influence the solution significantly. Considering both a blunt notch geometry and a sharp notch geometry in the computations permits a study of the relative roles of high strain and high triaxiality on failure. Comparison is made with published experimental results for notched tensile specimens of high-strength steels. All axisymmetric specimens analyzed fail at the center of the notched section, whereas failure initiation at the surface is found in plane strain specimens with sharp notches, in agreement with the experiments. The results for different specimens are used to investigate the circumstances under which fracture initiation can be represented by a single failure locus in a plot of stress triaxiality vs effective plastic strain.