Research On The Fatigue Strength And Simulation Platform Of Vehicle

For the actual need of fatigue strength and fatigue reliability analyses of the key parts in the vehicle industry, the paper summarized the vehicle fatigue simulation and analyses flow ultilizing MBS, FEM, Fatigue data reduction system and other software tools. On the basis of data analysis system of vehicle dynamic stress testing and vehicle fatigue simulation system which were developed by ourselves, the structure of vehicle fatigue simulation distribution platform based on gluing algorithm was set up. Data exchange and collaborative method among multiply disciplinary were discussed in detail. The platform integrated with commercial software has a friendly, open and easily removable interface and is valuable for practical use. The paper also discussed the application of cloud computing to the vehicle fatigue strength simulation platform.According to the line rolling stock dynamic stress test, based on the fatigue strength assessment and fatigue life prediction theory, we developed a set of experiment data processing system using c++and delphi. The system has the characteristics of seamless combination with test hardware; automatically generating test report; good interaction; great portability and so on. Based on the traditional tri-peak rain-flow counting algorithm, in view of a large amount of data, we realized the improvement of rain-flow counting method to satisfy the need of cycle count of the massive data in the line dynamic stress test. The software has been applied to the dynamic stress test data processes in some railway lines, such as the dynamic stress measurement data of heavy haul train for DaQing Line which was discussed in this paper. The stability of the software and the reliability of the analyzed results has been verified.Acquirement of the dynamic stress-time history is the key to fatigue life analysis and prediction. The software tools have been developed by means of testing in real field and numerical simulation. In addition, on the basis of stress/strain modals theory, a new method of obtaining dynamic stress-time history was put forward, which can ascertain the maximum stress/strain time history via other measured data and predict the fatigue life more precisely.On some specific positions, the dynamic stress-time history can't be measured with strain gauge directly. Therefore, this paper presented a stress hybrid calculation method based on experimentation and numerical simulation. Based on inverse method named SRM(Sensor Response Method), the calculation formulas were deduced in detail in the paper. On the basis of these formulas, a software system using c++and Matlab was developed for vehicle bogie stress prediction. The strength experiment of CRH2bogie show that the stress can be obtained by the proposed method expediently and accurately.