基于小样本数据的构件疲劳破坏全寿命区S—N曲线

发布时间：2018-02-28 04:03

本文关键词： 构件疲劳破坏全寿命 S—N曲线小样本双对数双折线一元线性回归升降法　出处：《中国铁道科学》2017年05期 　论文类型：期刊论文

【摘要】：针对传统S—N曲线在构件疲劳破坏全寿命区适用性不强的问题,采用单点试验法对闪光对焊连接的HRB400高强钢筋标准试件进行高周疲劳试验,得到一系列小样本数据;然后基于小样本数据研究并提出适用于构件疲劳破坏全寿命区的双对数双折线S—N曲线。利用提出的改进肖维奈准则对第1段折线的试验数据进行取舍,然后根据一元线性回归原理得到第1段折线的方程;基于三参数幂函数曲线得到第2段折线的斜率和升降法确定的疲劳强度,求得第2段折线的方程;将2段折线方程联立,得到适用于构件疲劳破坏全寿命区的双对数双折线S—N方程。在此基础上,进一步研究并提出考虑置信度和可靠度条件下适用于构件疲劳破坏全寿命区的双对数双折线S—N曲线的计算方法。
[Abstract]:In order to solve the problem that the traditional S-N curve is not suitable for the whole life zone of fatigue failure of members, a series of small sample data are obtained by using the single point test method to carry out high cycle fatigue test on the standard specimen of HRB400 high strength steel bar connected by flash butt welding. Then, based on the small sample data, a double logarithmic double-fold S-N curve suitable for the fatigue failure life zone of the member is proposed. The test data of the first segment of the broken line are selected by using the improved Shawenet criterion. Then, according to the linear regression principle of one variable, the equation of the first broken line is obtained; the slope of the second segment and the fatigue strength determined by the ascending and descending method are obtained on the basis of the three parameter power function curve; the equation of the second segment broken line is obtained; A double logarithmic double broken line S-N equation is obtained for the fatigue failure zone of a member. The calculation method of double logarithmic double fold S-N curve which is suitable for the fatigue life zone of members under the condition of confidence and reliability is further studied and proposed.
【作者单位】：中南大学土木工程学院;中交城市轨道交通设计研究院有限公司;
【基金】：中国铁路总公司科技研究开发计划项目(z2014-038)
【分类号】：TG142.1

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