文献类型：期刊文献

中文题名：缺口圆棒低温断裂的局部法研究

英文题名：Study on Fracture of Notch Bars at Low Temperature with Local Approach

作者：惠虎[1];李培宁[1]

机构：[1]华东理工大学承压系统安全科学教育部重点实验室上海200237

年份：2009

卷号：45

期号：10

起止页码：306

中文期刊名：机械工程学报

外文期刊名：Journal of Mechanical Engineering

收录：CSTPCD;;EI(收录号：20094912531349);Scopus;北大核心:【北大核心2008】；CSCD:【CSCD2011_2012】；

基金：国家自然科学基金资助项目(50705029)

语种：中文

中文关键词：缺口圆棒;低温;解理断裂;局部法;数值模拟

外文关键词：Notch bar Low temperature Cleavage fracture Local approach Numerical simulation

摘要：对A508-Ⅲ钢两种缺口尺寸的缺口圆棒拉伸试样进行有限元数值模拟分析及低温断裂试验研究,研究结果表明,对于低温下脆断的缺口圆棒试样(断口呈解理断裂),起裂并非发生于弹性应力分布最大的缺口根部,而是在离开缺口根部有一定距离处,断裂时构件内部应力已非线弹性分布,而为弹塑性分布,采用基于线弹性有限元分析的应力场很难解释试验现象,而基于弹塑性有限元分析的应力场则能较好解释试验结果。基于解理断裂局部法理论,采用数值模拟方法预测不同缺口半径的缺口圆棒试样的解理断裂概率-载荷曲线,提出44%的解理断裂概率所对应的预测载荷值与实际的平均解理断裂载荷值基本相等,在此基础上预测不同缺口半径的解理断裂载荷随缺口半径变化的趋势,并得到试验验证。
Fracture test and finite element analysis of two different sized notched tensile bars at low temperature are carried out. It shows that cleavage fracture initiates from the location ahead of the notch, not from the root of notch where the elastic stress is maximal. The stress distribution isn＇t elastic at fracture but elastic-plastic, so the result of elastic finite element analysis is contrary to the experimental results, otherwise, the result Of elastic-plastic finite element analysis accords with the experimental results. Based on cleavage fracture local approach theory, numerical simulation method is used to predict cleavage fracture probability-load curves of notch bars with different radius. The study shows that the predicted load value corresponding to 44% cleavage fracture probability of a structure is almost equal to the average value of actual cleavage fracture load. Based on this, the variation trend of cleavage fracture load vs. different notch radius is predicted and verified by test.