基于超声扫描的列车车轮轮辋径向裂纹缺陷重构

发布时间：2018-03-28 02:20

本文选题：超声波检测　切入点：车轮扫描　出处：《华东交通大学》2017年硕士论文

【摘要】：列车车轮的缺陷检测一直以来都是铁路运输部门高度关注的问题,车轮的安全性能对于车辆的运行极为重要,其隐含的缺陷是造成交通事故的重要因素之一。其中以列车车轮轮辋区的裂纹缺陷最为常见,目前针对车轮轮辋裂纹缺陷的检测方法较多各有优缺点,相关研究显示车轮轮辋缺陷的超声波检测是使用比较广泛的,其不仅检测高效、精度高而且检测成本低。通过对车轮轮辋缺陷的有效检测,对于实际的铁路安全运输具有重大意义。本文基于超声波检测理论基础和数值仿真模拟,通过车轮轮辋区径向裂纹缺陷超声波检测实验,来对车轮轮辋结构进行三维重构,以此来直观的反映缺陷的尺寸与位置结构;基于该种实验方法研制自动扫描系统来对车轮进行扫描检测并重构,以此验证该种重构方法的可行性和该扫描系统的实用性。本论文的主要工作如下:(1)数值模拟与实验。本文基于超声波检测基本原理,首先研究超声波在含有不同缺陷的车轮轮辋区的传播效应,并对其做数值仿真分析研究;然后通过做超声波扫描检测车轮缺陷实验,来对超声波在车轮内部传播作深入研究,从而定性地分析缺陷。(2)车轮三维重构研究。首先通过对超声波扫描车轮实验的超声信号进行分析与处理,提取信号特征;然后基于这些所获取的信号特征进行车轮三维重构技术。无缺陷车轮轮辋重构结果表明其重构与实际测量值的误差仅为2.67%;带缺陷车轮轮辋重构结果表明缺陷的识别效果较好,通过超声的扫描与检测实验,能重构出缺陷的大致尺寸与位置,从而直观的反映轮辋区所包含的径向裂纹缺陷。(3)自动扫描系统研制与实验。基于车轮扫描检测实验方法,设计并制作出了自动扫描检测系统,该系统基于单片机控制,以步进电机、丝杆螺母为传动件来引导超声探头对车轮进行圆周扫描,该系统可沿X、Y、Z轴移动和Z轴旋转,并对车轮的轮辋和辐板区域进行扫描。通过扫描系统采集的超声信号进行车轮结构三维重构,结果表明当自动扫描系统在轮辋扫描时给予电机每扫描一圈200个脉冲信号激励下,扫描系统运行的鲁棒性好,扫描检测的效果更好结果更准确,此时重构出的车轮三维结构效果最好。
[Abstract]:The defect detection of train wheels has always been a high concern of railway transportation departments, and the safety performance of the wheels is extremely important to the operation of vehicles. The hidden defects are one of the important factors causing traffic accidents, among which the crack defects in the wheel rim area are the most common, and there are many methods for detecting the wheel rim crack defects, which have their own advantages and disadvantages. Related studies show that ultrasonic detection of wheel rim defects is widely used, which is not only high efficiency, high accuracy but also low detection cost. Based on the theoretical basis of ultrasonic detection and numerical simulation, the structure of wheel rim is reconstructed by ultrasonic testing experiment of radial crack defect in wheel rim region. Based on the experimental method, an automatic scanning system is developed to detect and reconstruct the wheel. In order to verify the feasibility of the reconstruction method and the practicability of the scanning system, the main work of this paper is as follows: 1) numerical simulation and experiment. First, the propagation effect of ultrasonic wave in the wheel rim with different defects is studied, and then the ultrasonic wave propagation inside the wheel is studied by the ultrasonic scanning test. Thus qualitatively analyzing the defect. (2) 3D reconstruction of wheel. Firstly, the ultrasonic signal of ultrasonic scanning wheel is analyzed and processed to extract the characteristics of the signal. The reconstruction results show that the error between the reconstruction and the actual measured value is only 2.67, and the reconstruction result of the wheel rim with defects shows that the defect recognition effect is good. Through the ultrasonic scanning and testing experiments, the approximate size and position of the defects can be reconstructed, and the automatic scanning system can be developed and tested directly to reflect the radial crack defects contained in the rim zone. An automatic scanning and detecting system is designed and manufactured. The system is based on the control of single chip microcomputer, and the ultrasonic probe is used as the driving part to guide the ultrasonic probe to scan the wheel circumferentially. The system can move and rotate along the axis of XY Z and Z axis. The wheel structure is reconstructed by the ultrasonic signal collected by the scanning system. The results show that when the automatic scanning system is scanning the wheel rim, 200 pulse signals per lap are given to the motor. The running robustness of the scanning system is good, the effect of scanning detection is better and the result is more accurate. At this time, the reconstructed 3D structure of the wheel is the best.
【学位授予单位】：华东交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U270.33;TB559

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