基于激光超声体波的轨头内部缺陷检测方法研究  

Research on the internal defect detection method of rail head based on laser ultrasonic body wave

作　　者：廖韦韬 王海涛[1] 江奕 陈帅 郑凯[2] Liao Weitao;Wang Haitao;Jiang Yi;Chen Shuai;Zheng Kai(Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Special Equipment Safety Supervision and Inspection Institute of Jiangsu Province,Nanjing 210036,China)

机构地区：[1]南京航空航天大学,南京210016 [2]江苏省特种设备安全监督检验研究院,南京210036

出　　处：《仪器仪表学报》2021年第10期221-229,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金重大科研仪器研制(61527803)项目资助。

摘　　要：激光超声检测技术具有非接触、宽带宽和高分辨率的特点,针对常规超声对钢轨轨头内部核伤微小缺陷不敏感、定位定量检测难的问题,本文基于激光超声体波散射和衍射原理,提出了模态转换反射波和衍射波飞行时间的缺陷定位定量检测计算模型。通过COMSOL仿真建立了超声体波与内部缺陷相互作用的二维有限元模型,分析了钢轨内部缺陷处超声体波波模式转换状态,验证了定位及定量方法的可行性。其次,搭建了固定扫查激光超声实验检测系统,对不同埋藏深度和不同直径的孔缺陷进行B扫实验。实验结果表明,激光超声检测技术能有效的检测钢轨内部微小孔缺陷,基于所提出的计算模型和检测方法,对钢轨内部缺陷检测的定位相对误差在6%之内,定量相对误差在9%之内。Laser ultrasonic detection technology has the characteristics of non-contact,wide bandwidth and high resolution.The conventional ultrasonic is not sensitive to the small defects of nuclear damage inside the rail head,which is difficult to locate and quantitatively detect.In this study,the calculation model of the defect location quantitative detection based on the flight time of the modal conversion reflected wave and diffracted wave is proposed,which is based on the principles of laser ultrasonic body wave scattering and diffraction.By using COMSOL simulation,a two-dimensional finite element model of the interaction between the ultrasonic body wave and the internal defect is formulated.The model conversion state of the ultrasonic body wave at the internal defect of the rail is analyzed,and the feasibility of the positioning and quantitative method is verified.Secondly,a fixed scanning laser ultrasonic experiment detection system is established to implement B-scan experiments on hole defects of different buried depths and diameters.Experimental results show that the laser ultrasonic detection technology can effectively detect the micro hole defects in the rail.Based on the calculation model and the proposed detection method,the positioning relative error of the detection of the internal defects of the rail is within 6%,and the quantitative relative error is within 9%.

关 键 词：激光超声 体波 轨头 内部缺陷 衍射 

分 类 号：TH7[机械工程—仪器科学与技术] TB5[机械工程—精密仪器及机械]