基于双正交法的焊缝早期隐性损伤临界状态磁记忆特征

发布时间：2018-12-06 13:01

【摘要】：针对焊缝早期隐性损伤临界状态磁记忆特征提取及评价难题,在大量试验基础上提出双正交法:即焊缝检测路径的正交性和磁场矢量分析的正交性。以Q235B焊接试件为试验材料,通过测量焊缝纵向和横向磁记忆信号分布,引入磁场正交矢量空间图和李萨如图,研究疲劳载荷下焊缝隐性损伤演化的磁记忆表征规律,对比扫描电镜和X射线检测结果,获得焊缝早期隐性损伤临界状态磁记忆特征:隐性损伤出现时李萨如图会产生涡动性的局部闭合,随着损伤的扩展涡动性局部闭合的面积越来越大直至断裂时完全闭合。在此基础上提出正交矢量梯度积分S(K)和正交矢量合成梯度比Kr的概念,建立Kr与剩余寿命Nr定量关系模型,为焊缝早期隐性损伤临界状态的定量研究提供一种新的思路。
[Abstract]:In view of the difficult problem of extracting and evaluating the magnetic memory characteristics of the critical state of the early hidden damage of the weld, a biorthogonal method is proposed on the basis of a large number of tests: the orthogonality of the weld inspection path and the orthogonality of the magnetic field vector analysis. Taking Q235B welding specimen as experimental material, the magnetic memory characteristics of hidden damage evolution of weld under fatigue load were studied by measuring longitudinal and transverse magnetic memory signal distribution of weld seam, introducing magnetic field orthogonal vector space diagram and Lisaru diagram. Compared with the results of scanning electron microscopy and X-ray examination, the magnetic memory characteristics of the critical state of early hidden damage of weld seam were obtained. With the extension of damage, the area of local closure becomes larger and larger until the fracture is completely closed. On this basis, the concepts of orthogonal vector gradient integral (S (K) and orthogonal vector synthesis gradient ratio (Kr) are proposed, and the quantitative relationship model between Kr and residual life Nr is established, which provides a new idea for the quantitative study of the critical state of hidden damage in the early stage of weld.
【作者单位】：东北石油大学机械科学与工程学院;
【基金】：国家自然科学基金(11272084,11072056) 黑龙江省博士后科研启动基金(LBH-Q13035) 黑龙江省应用技术研究与开发计划(GA13A402)资助项目
【分类号】：TG441.7

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