金属磁记忆定量化评价的三维仿真分析与实验

早期损伤是导致金属构件发生突发性断裂的主要因素.针对大多数常规无损检测方法都只能对已成形的宏观缺陷进行检测,不能检测尚未成形的微观缺陷或应力集中区,以及金属磁记忆检测技术目前只能对早期微观缺陷进行定位,无法定量的问题,利用仿真与实验相结合的方法,建立了三维力磁耦合模型,仿真计算了微观缺陷表面空间三维磁场的分布,研究了应力、微观缺陷长度及扫描路径对磁记忆信号的影响,在此基础上,构建了金属磁记忆检测系统,实验研究了外加载荷、扫描路径与金属磁记忆信号的关系.研究结果表明:利用金属磁记忆检测技术可以实现对早期微观缺陷进行定量检测.

Dimensional Finite Element Simulation and Experimental Study of Metal Magnetic Memory Quantitative Evaluation

Early damage is the main factor that causes the metal structures fracture suddenly. Aimed at the condition that most of the non-destructive testing methods can only be used to detect the macro-defect formed already, but cannot be used to detect yet to microscopic defects, the metal magnetic memory testing technology can only be used to qualitatively determine the location of the zone of stress concentration but can''t be used to perform quantitative evaluation of the stress concentration zone, a method of combining simulation and experiment together is adopted to the research on the metal magnetic memory quantitative detection technology. A three dimensional force of Magnetic coupling model is established to simulate the three dimensional magnetic field distribution of the microscopic defects and research on the relationship between the stress, microstructure defect size, scan path of magnetic and magnetic memory signals. A metal magnetic memory testing system is constructed and the study of the relationship between the scan path and magnetic memory signals is performed. The experimental results and simulation conclusions are basically the same, and the use of the metal magnetic memory test technology can realize quantitative detection of the early microscopic defects.