基于材料磁特性的结构疲劳损伤磁测方法研究

发布时间：2018-11-19 10:39

【摘要】：结构疲劳损伤测量和评估方法的研究是一个难点。由于疲劳损伤伴随材料磁特性的变化,且磁测法测量简单方便,所以利用材料磁特性测量和评估结构的疲劳损伤具有实际意义。以Q235钢为试件,通过构建疲劳损伤磁测试验平台,研究了循环应力下,基于磁滞回线的结构疲劳损伤磁测法。结果表明,疲劳损伤不同,磁滞回线也不同。提取磁滞回线的矫顽力H_c和剩磁B_r作为特征量进行分析,结果显示,试件失效前的疲劳过程大致分为两个阶段:首先是H_c和B_r的快速增大阶段,该阶段的H_c和B_r对疲劳损伤的灵敏度较高;然后是H_c和B_r的变化缓慢阶段,该阶段的H_c和B_r对疲劳损伤的灵敏度较低。最后分析了H_c和B_r与疲劳累积损伤D的变化关系,能够为结构疲劳损伤的定量评估及在线监测技术的研究提供基础。
[Abstract]:The research of fatigue damage measurement and evaluation is a difficult problem. Because the fatigue damage is accompanied by the change of the magnetic properties of the material and the method of magnetic measurement is simple and convenient, it is of practical significance to use the magnetic properties of the material to measure and evaluate the fatigue damage of the structure. Using Q235 steel as a specimen, the magnetic measurement method of fatigue damage based on hysteresis loop under cyclic stress was studied by constructing a magnetic testing platform for fatigue damage. The results show that the hysteresis loop is different with different fatigue damage. The coercivity Hac and the remanent magnetic Blives r of the hysteresis loop are extracted for the analysis. The results show that the fatigue process before the failure of the specimen is roughly divided into two stages: first, the rapid increase phase of H _ S _ c and B _ r. At this stage, the sensitivity of HAC and BSCL to fatigue damage is higher. Then there is the slowly changing phase of HSCs and BARs, which have lower sensitivity to fatigue damage. Finally, the relationship between hsc and BCST and fatigue cumulative damage D is analyzed, which can provide a basis for the quantitative evaluation of fatigue damage of structures and the research of on-line monitoring technology.
【作者单位】：中国特种设备检测研究院;
【基金】：863课题(2015AA043702)项目资助
【分类号】：TB302.5

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