作者:陈怀宁, 胡凯雄, 吴昌忠
作者单位:中国科学院金属研究所, 辽宁 沈阳 110016
关键词:残余应力; 测量不确定度; 压痕应变法; 误差; 分析
摘要:
压痕应变法是近期出现的一种非常有价值的(焊接)残余应力测量技术,它具有无损、快捷、精确、成本低等特点。采用该技术测量残余应力时的误差大小或不确定度分析是人们关注的问题之一。应用B类评定法对采用该技术测量Q345低合金钢中焊接残余应力的不确定度进行了详尽分析,结果表明,应力相对不确定度的大小主要决定于应变的绝对值,低应变情况下的相对不确定度主要由重复性试验的应变不确定度决定。一般情况下,应力的标准不确定度数值为20~30 MPa。
Uncertainty evaluation in measuring residual stress by indentation strain method
CHEN Huai-ning, HU Kai-xiong, WU Chang-zhong
Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Abstract: The indentation strain method is a valuable residual stress measurement technique. It is nondestructive, rapid, and cost-effective with high precision. The measurement error or uncertainty is one of main factors concerned. A detail analysis has been demonstrated in measuring residual stresses in steel Q345 by the method with B-type measurement uncertainty evaluation. The results indicate that the relative stress uncertainty mainly depends on the absolute value of the strain and the strain uncertainty of repetitive test governs the relative strain uncertainty under lower strain values. Generally speaking, the amount of the stress standard uncertainty is 20~30 MPa.
Keywords: Residual stress; Measurement uncertainty; Indentation strain method; Error; Analysis
2010, 36(1): 24-27 收稿日期: 2009-4-20;收到修改稿日期: 2009-7-5
基金项目:
作者简介: 陈怀宁(1962-),男,江苏连云港市人,研究员,主要从事焊接残余应力的控制和测试技术方面研究。
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