基于磁记忆检测技术的接触损伤评价与反演的机理和方法研究

This project is to apply metal magnetic memory (MMM) technique to the investigation of the early contact damage, mainly though experiment, together with theoretical analysis and numerical simulation. The detailed contents are as following: firstly, systematic experimental research of contact damage will be carried out to examine the effect of different loading methods on the magnetic domain structure. After the magneto-mechanical coupling effect is determined, the corresponding damage criteria upon on MMM technique will be improved. Then the relationship between magnetic flux leakage signals and defect feature parameters and its sensitivity are to be analyzed. By combining date identification technology and experimental testing together, the inversed effect identification method based on MMM technology will be proposed to quantitatively investigate some typical defects. Finally, by using the effective inverse method developed, we can obtain the leakage magnetic field expression of some typical defects, and make comparison with earlier experimental results. The project is of great significance for the promotion of the initial evaluation damage of materials and structures, and for the development of new non-destructive testing techniques.

本项目将基于金属磁记忆技术，主要针对接触损伤这一损伤形式，开展以实验研究为主，结合理论分析和数值计算进行研究，具体研究内容包括：首先进行系统的接触损伤实验研究，分析不同加载方式对磁畴结构和磁畴运动的影响。接着确定相关力磁耦合机制，进一步完善利用金属磁记忆法进行检测的相关损伤判据；在上述基础上，分析不同漏磁信号与缺陷特征参数之间的关联与敏感程度，将数据识别技术与实验测试技术相结合，提出基于磁记忆无损检测的缺陷识别反演方法，利用若干典型缺陷进行定量分析，在此基础上，发展有效的反演技术；获得一些典型缺陷的漏磁场表达式，并与实验结果相比照。该项目的执行对开展材料与结构早期损伤检测和促进新的实验技术的发展具有重要意义。

本项目基于金属磁记忆技术，系统开展了样品制备、实验研究，使用不同形状的压头进行接触和冲击实验，具体分析了不同工况对漏磁信号的影响，初步确定了相关力磁耦合机制，进一步完善了利用金属磁记忆法进行检测的相关损伤判据；分析了漏磁信号特征参数及对缺陷特征的敏感程度；进一步开展了金属磁记忆方法的实验研究和数值模拟；通过将实验结果和数值分析结果相比照；开展了基于电磁无损检测技术的缺陷反演技术。通过第一原理计算，初步得到交换积分常数和应力之间的关系，建了应力导致磁化的微观理论模型。并结合之前实验数据进行对比，验证了理论的合理性。该项目的执行对开展材料与结构早期损伤检测和促进新的实验技术的发展具有重要意义。