The Load And Dynamic Stress Tracking Test Research For CRH380AL EMU On Beijing-Guangzhou Line

In the background of Beijing-Guangzhou dynamic load and stress tracking test for CRH380AL high speed electrical multi units (EMUs). Based on the force transducer for axle spring and rotating arm, record the vertical and lateral load data. Select the data around the wheel repair from Zhuozhou east to Baoding east and have a detailed dynamic load analysis which include time domain, frequency domain and statistics covering both high speed running and turnout passing operation conditions. Search exactly the data from the same line by the improving correlation algorithm in different days. In the statistics aspect, process the data with the method of Rain-flow, Then combine the method of adaptive histogram and random average shifted histogram (RASH) to have a contribution to finding distributed parameters according with some confidence level. Research the characteristics in the frequency domain during the parking time, Then determine the frequency location disturbed by electricity, moreover define principle to recognize mechanical vibrations. These preprocessing method improve the reliability and precision of evaluation. The new analysis shows:(1) Under the speed of200km per hour, the probability of heavy load have a significant increase, and this regularity almost completely depend on velocity. In addition, it has little relation with speed up or slow down. When the speed pass200km per hour, the probability of heavy load remain keep high level, but the statistic characteristics are influenced by multi-factor such as velocity, zone, speed up or slow down, etc. As regard to lateral load, when the speed go through from100km/h to200km/h, the lateral vibration become intensely, and unmatched lognormal distribution. When the speed go above200km/h, the lateral load amplitude meet lognormal distribution again.(2) The vertical and lateral stress statement have an improvement after wheel repair. Among all the results, the amplitude of vertical and lateral load during The turnout passing have a little improvement.(3) In the velocity of300km/h. the energy of periodic vibration from railway track board is the highest, the second is periodic rotary movement from wheel set. The frequency in92.89Hz exist stably before wheel repair Then disappear after wheel repair. The periodic vibration have something to do with defect of wheel. As regard to lateral load, The periodic vibration caused by railway track board still distinct, the second is periodic lateral movement, the third is the periodic rotation of wheel set. When the speed keep on the velocity of 130km/h, the periodic effect from track board and periodic rotation become implicit. The frequency peak disappear in the first envelope and the first envelop move towards low frequency evidently.(4) As regard to high speed running operation condition, the probability of occurrence for heavy load decline. The probability of lateral load have a slight increase. For the turnout passing, both vertical and lateral have a little decline.(5) With the increase of running distance, the equivalence stress of fatigue weak spot near weld joint have little change, moreover less than70MPa, meet the requirement running12million kilometers safely.