| Over the past 20 years, although there has been great development in the railway in our country, the capacity of railway is still far from meeting the need with the development of society and economy. In order to accelerate the development speed of railway construction, it has entered a period of great development with high-speed and heavy haul in our country.Body structure is an important load-bearing component of electric locomotive. It is an important and indispensable work to analyze structural strength and assess fatigue life of car body in the design and manufacture of high-speed and heavy haul vehicles. The accidents of fatigue fracture still occur in the transformation of vehicles and new types of vehicles, which shows that the analysis method of fatigue reliability of rolling stocks has a wide gap between actual. Therefore, it is an urgent and important research topic to study the evaluation method of fatigue reliability for high-speed and heavy haul rolling stocks and its fatigue assessment.Load cases which are tally with the actual situation for the strength analysis of locomotive body are put forward on the basis of the reference of the technical standards at home and abroad and the design requirement of heavy haul electric locomotive. The stiffness and strength are analyzed and the structural rationality is evaluated by FEM. Then, the suggestions for improvement are put forward for car body structure according to the results and potential problems.For the evaluation of fatigue strength and reliability, the dangerous position which may occur fatigue damage is determined on the basis of stress amplitude considered by greater stress position under static strength and the fatigue load of European standard EN12663. Then make further analysis on details of its geometry, welded joints type and process characteristics on the basis of the dangerous position which may occur fatigue damage, and judge the possibility of fatigue damage. The reasonable improvement measures are put forward for the dangerous position found by research.The results of structural analysis shows that there has unreasonable sites for the overload of body structure, and the results can meet the requirement of strength and stiffness of body structure and reduce the deadweight effectively on the basis of the scheme of structural improvement. There has positions which are indeed a high risk of fatigue fracture according to the study of dangerous positions may cause fatigue damage, and some corresponding preventing measures are put forward. The result not only provides important basis for the design and manufacture of DBC 9600kW AC drive electric locomotive, but also has an important theoretical role for the research of fatigue life evaluation method of rolling stocks. |
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