Reconstruction Of Radial Crack Defects Of Train Wheel RIM Based On Uitrasonic Scanning

Defect detection of train wheel has always been highly concerned about the railway transportation department,the safety performance of the vehicle wheel for operation is very important,the underlying defect is one of the important factors causing traffic accidents.The crack of train wheel rim area is the most common,at present there are many methods for detecting defects of wheel rim crack have advantages and disadvantages,according to the research of ultrasonic detection of wheel rim defects is widely used,not only the detection efficiency,high precision and low detection cost.It is of great significance to effectively detect the defects of the wheel rim,which is of great significance for the safe transportation of the railway.In this paper,based on the theory of ultrasonic testing and numerical simulation,the radial wheel rim area crack ultrasonic detection experiments for the three-dimensional reconstruction of the wheel rim structure,to visually reflect the size and location of defects;Based on the experimental method,an automatic scanning system is developed to detect and reconstruct the wheel,which verifies the feasibility of the method and the practicability of the scanning system.The main work of this paper is as follows:(1)N umerical simulation and experiment.In this paper,based on the basic principle of ultrasonic testing,the effect of ultrasonic wave on the wheel rim region with different defects is studied;And then through the ultrasonic scanning wheel defect test,to study the propagation of ultrasonic waves in the interior of the wheel,so as to qualitatively analyze the defects.(2)3D reconstruction of wheel.Firstly,the ultrasonic signal is analyzed and processed to extract the signal characteristics;Then,the 3D reconstruction technology of the wheel is obtained based on the acquired signal features.The reconstruction results show that the reconstruction error of the wheel rim is only 2.67%;The reconstruction results of the wheel rim with defects show that the recognition effect is better.By means of ultrasonic scanning and testing,the size and position of the defects can be reconstructed,and the radial crack defects in the rim region can be directly reflected.(3)Development and experiment of automatic scanning system.Based on the experimental method of wheel scan detection,an automatic scanning detection system is designed and manufactured.The system is based on the single chip microcomputer control,and the stepper motor and the screw nut are used to drive the ultrasonic probe to scan the wheels,and it can be moved along the X,Y,Z axis and the Z axis,and the wheel rim and spoke area scanning.Three dimensional reconstruction of wheel structure by ultrasonic signals acquired by scanning system,the results show that when the automatic scanning system is used to scan the rim and the number of motor pulses per sweep is 200,it has good robustness,and the result of scanning detection is more accurate,at this time the reconstruction of the wheel three-dimensional structure of the best results.