Theory And Test Analysis Of High-Speed Bogie Frame Under Random Loading

With the Rolling Stock towards to overload and high speed development, the actual service condition of vehicle components has become much more complex, its safety and reliability has to be more and more attention.As the bogie frame which works under random load in long-term,its fatigue reliability problems directly related to driving safety.Therefore,it is very important to study the fatigue strength of bogie frame under the random load.Based on consulting plenty of domestic and foreign literature about the fatigue strength theory and test research of bogie frame under random load,the thesis uses the high-speed welded bogie frame as research object.Firstly,the random load spectrum of several typical working conditions was obtained by dynamics simulation,then the stress time history of bogie frame was got through the dynamic stress calculation by using finite software ABAQUS.Meanwhile,this thesis analyses the influence factors of dynamic stress of bogie frame about the different service environment and considered carbody flexibility.In the thesis,the dynamic stress test of random load loading,block spectrum loading and amplitude cycle load loading were done in the lab.Through the tests,the dynamic stress of the bogie frame was obtained.Used the weld level of different parts and S-N curve and based on the fatigue accumulating damage theory,the fatigue life of frame was evaluated.By comparing and analyzing the results of simulation and tests,the feasibility of random loading dynamic stress test in the lad was proved.lt provides an efficient way for the fatigue strength assessment of high-speed bogie frame in our country.The load spectrum of accelerated fatigue tests was studied in the thesis.The block spectrum and the random load spectrum were generated by using the level crossing counting method and the rainflow time-domain reconstruction method based on damage equivalent principle and damage distribution consensus principle.