【作者】 白洁； 彭建平； 张康； 冯舲帆； 高晓蓉；

【Author】 Jie BAI;Jian-ping PENG;Kang Zhang;Ling-fan Feng;Xiao-rong Gao;School of Physical Science and Technology,Southwest Jiaotong University;

【机构】 西南交通大学物理科学与技术学院；

【摘要】 在机车运行过程中车轮与钢轨间的滚动接触使车轮表面易出现滚动疲劳裂纹(RCF),当裂纹中存在第三种介质对裂纹进行填充并引起裂纹闭合时,会影响裂纹的检出率(POD)。第三种介质填充裂纹区域表现出弱导电性问题,影响电涡流分布,掌握裂纹状态将有助于量化评估材料疲劳状态。文章基于涡流脉冲热成像方法对裂纹锈蚀异物填充进行检测,研究裂纹在弱电导状态下的涡流分布特性。通过仿真对比裂纹填充物质时,在加热阶段所对应的不同深度的涡流密度场分布,研究疲劳裂纹闭合的检测。利用试块生锈方式实现角度裂纹填充并开展测试,结果显示与仿真结论相吻合。更多还原

【Abstract】 Rolling contact force between the wheel and the rail during the running of the locomotive causes the rolling fatigue cracks(RCF) appearing in wheel tread. The fatigue crack closes with the third medium filling in the crack gap, which causes the decreasing of probability of detection(POD). The crack region filled with the third medium has a weak conductivity, where the distribution of eddy current displays a different phenomenon comparing with opening crack. Mastering the crack region state would help quantify the fatigue state of materials. Based on the Eddy current pulsed thermography(ECPT) method, the crack filled with corrosion was detected and its characteristics of the eddy current distribution had been studied in a weak conductance state. The detection of fatigue crack closure is studied and the difference of the eddy current distribution between open crack and closed crack during heating stage is compared in different depth through the simulation method. The oblique crack with corrosion is made and tested, the results are in good agreement with the simulation results.更多还原