Experimental Study On Ultrasonic Testing Of Wheel Rim Damage

With the development of China's transport industry,the train has become an indispensable means of transport in people's production and life,including daily travel and transportation of energy goods and has been inseparable from the train.Along with the increase of railway transport density,it has become necessary to impoly Large Maintenance Machine to railway constuction.According to the data released by “The Forecast for The Market Demand of China Railway Vehicles and The Manufacturing of High-speed Railway Vehicles and The Analysing Report for Investment Strategy for 2017-2022”,the amount of Large Maintenance Machine will be around 3000 sets by the end of the 12 th five-year whose work area will cover not only the main busy railyway lines but also the speed-up railyway lines.Therefore,its security is self-evident.The wheel rims of the train are prone to crack during the manufacturing and long-term operation,resulting in the rupture of the entire wheel,causing serious traffic accidents.Therefore,this paper mainly deals with the defects of the rims.In the process of long-term use of the wheel,it is prone to stress concentration,damage,cracks and other defects,many defects we can not be identified by the naked eye,so nondestructive testing will become the best detection of these defects.The main content of this thesis aim at the challenge of detecting curved surface of rotary workpiece,adopt the ultrasonic NDT,and research on automatic ultrasonic testing technology,then develop a multiple-axis testing system to accomplish the aim of detecting.This system can be used to detect residual stress and flaw,and the transducer should be move along the profile of workpiece,also the beam axis of transducer need to be aligned with the normal of surface,so we need to make the path generation before detecting so that the transducer can be in the best position.This system consists of Industrial Personal Computer,driving mechanism,transceiver device,motion control system,transducer and so on.The key to this system is the designing of 6-axis device and the linkage of multiple axis,also the ultrasonic signal should be synchronized with the axis.The wheel hub is one of rotary workpiece,the surface of wheel hub is made up of flat surface,curved surface and other complex surface,we have detected the wheel hubs to prove that this system can be applied to complex profile.Meanwhile,the software system can visualize defects,and give out the position and dimensions of defects.So it is efficient and reliable to automatic detect flaws for rotary workpiece of this system.