航空金属套管结构脉冲远场涡流检测机制及探头优化

航空金属套管结构凭借其套管管材可选择性组合的特点,有力提升了航空管道服役过程中的结构安全性与稳定性,因此广泛应用于航空、航天等领域的重要装备中.为进一步保障航空金属套管结构的服役安全,需采用有效的无损定量检测方法定期对其进行检测和损伤评估.围绕不锈钢-碳钢双层航空金属套管的无损定量检测,着力探究脉冲远场涡流检测机制及检测探头优化.通过快速有限元仿真研究,明晰磁场及坡印廷矢量在套管内外空气域中的分布规律、远场区识别手段等,并基于此,深入探索电磁屏蔽结构及其在检测探头优化中的有效性.结合仿真研究,对航空金属套管腐蚀减薄缺陷检测进行了实验探究,通过实验进一步验证所提航空金属套管结构脉冲远场涡流检测的远场区识别方法以及基于电磁屏蔽的探头优化成效.

Testing Mechanism and Probe Optimization of Remote Field Pulsed Eddy Current Evaluation of Aviation Metallic Casing Pipes

Relying on its advantages of flexible combination of casing pipes, the structure of Aviation Metallic Casing Pipes (AMCPs) is widely applied to the important equipment in the field of aviation and spaceflight, enhancing the safety and stability of aviation pipeline service. In order to further guarantee the long term safety and structural integrity, it is indispensable to periodically inspect AMCPs and evaluate defects via effective Nondestructive Evaluation (NDE) techniques. In light of this, this paper intensively explores the testing mechanism and probe optimization of Remote Field Pulsed Eddy Current (RFPEC) evaluation of a typical AMCPs structure which includes stainless steel and carbon steel casing pipes. The distributions of Poynting vectors and magnetic field within the internal and external regions of AMCPs are analyzed by fast finite element modeling. Based on this, a method for localization of remote field is proposed. Following this, the Electromagnetic Shielding Structure (EMSS) for probe optimization is intensively investigated. Parallel to the simulations, a series of experiments for evaluation of wall thinning defects in ACMPs are carried out by using the built up testing system. The recognition method is valid.