交变激励下钢轨表面裂纹的磁场畸变量重构

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关键词：钢轨；滚动接触疲劳；无损检测；交流电磁场检测；磁场响应中图分类号：TH89DOI：10.3969/j.issn.1004-132X.2025.04.020 开放科学（资源服务）标识码（OSID）：

Reconstruction of Magnetic Field Responses Caused by Rail Surface Cracks with Alternative Current Excitation

WANG Chi1'² ZHOU Yu1，2 ？ WENG Zhiyi1，2 1.Key Laboratory of Road and Traffic Engineering of the Ministry of Education，Tongji University， Shanghai，201804 2.Shanghai Key Laboratory of Rail Transit Structure Endurance and System Safety，Tongji University，Shanghai，201804

Abstract： As the response laws of the perturbed magnetic field in ACFM to rail RCF crack morphology parameters remained unclear，a novel method was proposed for functional reconstruction between the ACFM perturbed magnetic field and rail RCF crack parameters. The ACFM calculation models were established based on multiple field tests of surface length，elipse ratio，and internal angle of RCF cracks in heavy-haul railway rails throughout their full life cycle. The perturbed magnetic field above RCF cracks with different parameters was numerically calculated using the ACFM model. The relationship between RCF crack parameters and the perturbed magnetic field was systematically analyzed. Through fiting and evaluation of the perturbed magnetic field's response to the spatial morphology parameters of RCF cracks， the functional expression of the response laws was reconstructed. The results demonstrate that the ACFM response to rail RCF crack parameters is synthetically characterized. The peak value of magnetic field x -component is observed to increase linearly with the surface length and nonlinearly with the internal angle of RCF cracks.Conversely，a nonlinear decrease may be identified as the ellipse ratio of RCF cracks increases. These variations are effectively described by polynomial functions. The change rules between the perturbed magnetic field and RCF crack parameters may be functional reconstructed. The determination coeficient between the reconstructed results and the perturbed magnetic field is found to exceed 0.99，while the sum of squared errors（SSE） and root mean squared errors（RMSE） are constrained to less than O.Ool 15 and 0.Oo3，respectively.

Key words： rail;rolling contact fatigue（RCF）； non-destructive testing； alternative current fieldmeasurement（ACFM） ；magnetic response

0 引言

在轮轨接触引起的周期性切向力与牵引力反复作用下，钢轨表面特别是轨距角应力集中区域极易因滚动接触疲劳（rollingcontactfatigue，RCF）而产生裂纹。（剩余12519字）