多尺度复合损伤的匀场激励磁场梯度暂态涡流定量评估关键技术研究

Nonmagnetic conductors are widely employed in key structures and apparatus in such engineering fields as aerospace, power energy and so on. Within the stress environment, in-service nonmagnetic conductors usually operate with macroscopic flaws, and thus are subject to multi-scale defects which integrate microscopic damages with macroscopic anomalies. It is highly demanded that the multi-scale defects in nonmagnetic conductors can be detected as well as quantitatively evaluated. In this project, the influence of multi-scale defects on electrical properties of nonmagnetic conductors will be systematically analysed via experiments and simulations regarding mechanics and electromagnetism. The correlation of the multi-scale defect with the testing signal and its features will be established. Following these, the method involving evaluation and reconstruction of multi-scale defects will be proposed. The tasks of the proposed project include: (1) analysis of the influence of multi-scale defects on electrical properties of nonmagnetic conductors; (2) investigation regarding correlation of the multi-scale defect with the gradient-field signal and its features; and (3) establishment of the algorithm for evaluation and reconstruction of multi-scale defects. The proposed research is beneficial to the application of electromagnetic non-destructive evaluation (ENDE) in safety assessment of structures and apparatus, and has significance regarding development of ENDE for quantitative evaluation of in-service metallic components.

在航空航天、能源等领域的工程结构与装备中广泛采用非铁磁性金属构件。在役非铁磁性金属构件往往在应力环境中带缺陷运行，易形成微观损伤与宏观缺陷共存的多尺度复合损伤，对其进行无损定量评估对结构与装备安全具有重大意义。本项目将通过力、电磁仿真和试验研究，揭示多尺度复合损伤对非铁磁性金属构件电磁特性的综合影响机理，阐明检测信号及其特征对该损伤的响应规律，系统解决非铁磁性金属构件多尺度复合损伤定量评估与重构精度提升的关键问题。项目将从以下几个方面开展研究工作：1）多尺度复合损伤对非铁磁性金属构件电磁特性综合影响机理的分析；2）暂态磁场梯度信号及其特征对多尺度复合损伤响应机理的探究；3）多尺度复合损伤定量评估与重构精度提升手段、相关理论和实现方法的建立。本项目将为电磁无损定量评估技术在结构与装备安全评估及维护中的应用推广奠定基础，对促进在役金属构件缺陷无损定量评估技术的实际应用具有重要意义。

本项目针对航空航天、能源等领域工程结构与装备中广泛采用的非铁磁性金属构件可能出现的微观损伤与宏观缺陷共存的多尺度复合损伤，提出磁场梯度脉冲涡流无损定量检测新技术，通过力、电磁仿真和试验研究，揭示了多尺度复合损伤对非铁磁性金属构件电磁特性的综合影响机理，进一步阐明检测信号及其特征对该损伤的响应规律，系统解决了非铁磁性金属构件多尺度复合损伤定量评估与重构精度提升的关键问题。项目主要研究工作及结论包括：1）揭示了多尺度复合损伤对非铁磁性金属构件电磁特性综合影响机理；2）明晰了暂态磁场梯度信号及其特征对多尺度复合损伤响应机理；3）确立了多尺度复合损伤定量评估与重构精度提升手段、相关理论和实现方法。本项目成果为电磁无损定量评估技术在结构与装备安全评估及维护中的应用推广奠定了基础，进一步促进了在役金属构件缺陷无损定量评估技术的实际应用。