Fatigue Life Assessment Of Aluminum Alloy Welded Bolster For Metro

With the development of rail transportation vehicle, the development levels also gradually improve. Aluminum alloy material has better physical and mechanical properties, widely used in rail vehicle. As the traction drive link between the train frame and the bogie, and the body bolster is body under vertical force and vertical to the cross site, which is closely related to the vehicle running safety and reliability.Welded structure is currently the most widely used connection mode, it saves material and reduce drilling, assembly processes, simplifying the process; and it can in accordance with the requirements of the selection of materials, with a good economy; welding structure of airtight and water tightness is good, rigid structure is larger, the structural integrity of the good. But due to the welding process will inevitably accompanied by various defects, resulting in the weld is the weakest link, the vast majority of fatigue accidents occurred at the weld site. Found in the maintenance process bolster weld fatigue crack, which to the safe operation of the subway caused a serious threat; therefore to bolster aluminum alloy weld fatigue research is very necessary.The main research contents of this paper are as follows:First of all to bolster Singapore aluminum alloy train body as the research object, to bolster for analysis and calculation of static strength and its weak parts. For sleeper beam static strength test and acquisition measuring point data, bolster26test point selection, finite element static strength calculation results and the test results were compared. The results show the corbel design results meet the requirements.Then the new welded structure fatigue life prediction method "main S-N curve method", to bolster68main weld structure stress analysis and life prediction, and to bolster fatigue strength test. The results of comparison analysis and the results of life prediction and fatigue test.The bolster to fill strong test, results and bolster did not fill the test compared complement, supplement schemes can improve the anti fatigue ability of the bolster. And for those which do not meet the weld fatigue life design life of the structure is improved, to bolster the improved use main S-N curve method to carry on the evaluation of life, the life of weld has increased.