钢轨轨脚裂纹红外热波无损检测实验

目前,超声检测在钢轨裂纹检测中得到了广泛的应用,但在钢轨裂纹检测过程中,超声波检测方法存在一定的盲区,未能检测到轨脚两侧的裂纹.针对超声波检测方法的不足,搭建了一种红外热波钢轨踏面裂纹无损检测平台.钢轨裂纹红外热波无损检测平台是红外无损检测领域的一个新的研究方向,实验平台的建立主要包括3部分:热激励源的选择、实验平台的搭建、红外图像的提取.该技术用于通过热激励源加热轨底表面.根据热波理论,钢轨表面到轨底内侧的传热过程受钢轨的物理特性和内部结构的影响,如果钢轨内部存在缺陷,则缺陷类型会影响钢轨表面的温度分布.根据钢轨表面温度信息的分布,确定钢轨内部缺陷的位置,达到检测钢轨裂纹的目的.实验结果表明,裂纹对应的轨底表面温度高于无裂纹对应的轨底表面温度,证明红外热波无损检测对钢轨裂纹检测是可行的.

Experiment into Nondestructive Testing of Rail Foot Cracks Using Infrared Thermal Waves

At present,ultrasonic testing is widely used in rail crack detection.However,in the process of rail crack detection,there is a certain blind spot in this method,and cracks on both sides of the rail foot are not detected.Aiming at these shortcomings,an infrared thermal wave nondestructive testing platform for detecting cracks on the rail foot is proposed in this paper.Infrared thermal wave nondestructive testing for rail cracks is a new research area in the field of infrared nondestructive testing,and the establishment of the experimental platform mainly includes three parts:the selection of the thermal excitation source,the construction of the experimental platform,and the extraction of the infrared images.The technology is used to heat the surface of the rail foot through a thermal excitation source.According to the wave theory of the heat transfer from the surface to the inside of the rail foot,the transfer process can be affected by the rail’s physical characteristics and internal structure.If there are defects inside the rail,the distribution of the temperature on the rail surface will be affected according to the type of defect.The location of the internal defects of the rail can be determined according to the distribution of the surface temperature information of the rail,thereby achieving the goal of crack detection in the rail.Experimental results show that the surface temperature of the rail foot corresponding to the crack is higher than the corresponding rail foot surface temperature without cracks,proving that infrared thermal wave NDT(non-destructive testing)is feasible for rail crack detection.