Abstract:Research purposes: There have various combined loads on vehicles in the moving process. Because of variety factors,such as ovality of wheel,attack of vehicle at curve rail,rail slot,turnoff,fatigue crack's initiation and growth~ influenced by the moment of flexure which was induce by the normal force existing between wheel and rail in the course of vehicles running. The growth behavior of fatigue carck of U71 Mn and PD3 rail steel under moment of flexure condition was investigated using NENE-2 fretting test machine. Based on the results, measures are proposed to avoid fatigue damage.
Research results: The results indicate that the crack initiate in the stress focus position , and the impact of main shear stress is very important. The growth of crack under static load is different from dynamic load condition. Under the same loading rate, the crack of PD3 rail is easier to initiate and grow than U71Mn's. To prevent and mitigate fatigue damage, suitable materials must be chosen based on the type of the rail line and work environment. PD3 rail steel would be used at heavy haul railway. U71 Mn rail steel would be used at high-speed railway.
胡家杰,王文健,钟雯,刘启跃. 弯矩作用下钢轨疲劳裂纹扩展行为研究弯矩作用下钢轨疲劳裂纹扩展行为研究[J]. 铁道工程学报, 2008, 25(9): 26-29.
HU Jia-jie, WANG Wen-jian,ZHONG Wen,LIU Qi-yue. Research on the Growth of Fatigue Crack of Rail Steel under Moment of Flexure Condition. 铁道工程学报, 2008, 25(9): 26-29.
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