多频涡流裂纹重构方法及其在金属夹芯板焊部裂纹定量检测中的应用

金属栅格夹芯板是近年来出现的一种新型多功能材料,在航天航空、舰船和铁路运输等方面具有广阔应用前景。夹芯板焊接部位若出现裂纹损伤将会对材料的力学性能和结构的安全性产生极大影响。目前尚无完善的金属栅格夹芯板定量无损检测方法。利用涡流检测技术,对夹芯板焊接部位裂纹定量检测进行了理论和试验研究,提出了一种基于多频检测信号进行裂纹重构的反问题方法。通过对十字涡流检测探头所得焊部检测信号进行反演,证实了多频涡流检测裂纹重构方法对夹芯板焊部裂纹定量检测的有效性。

A Multi-Frequency Inversion Algorithm and its Applications in Quantitative NDE of Cracks in Welding Joints of a Metallic Lattice Sandwich Plate

Lattice sandwich metallic plate（LSMPI is a new type of multifunctional material, which is useful in many important industries for its special mechanical behaviors. Cracks in the welding joints of the LSMP may significantly reduce the material strength and, consequently, influence the safety of structure. Up to now, there is still no satisfactory nondestructive evaluation{ NDE） method being developed for the quantitative NDE of LSMP. In this paper, an inversion scheme is put forward for the reconstruction of cracks in welding zone from Eddy Current Testing（ECT） signals based on a strategy of multi-frequency inspection. The ECT signals obtained by using a cross- type ECT probe are used to reconstruct profiles of cracks in welding zone. Good consistency of the reconstructed and the true crack profile is obtained, which confirms the validity of the new scheme to NDE of LSMP.