|
|
|
| Research on the Growth of Fatigue Crack of Rail Steel under Moment of Flexure Condition |
| HU Jia-jie, WANG Wen-jian , ZHONG Wen , LIU Qi-yue |
| Southwest Jiaotong University, Chengdu,Sichuan 610031.China |
|
|
|
|
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.
|
|
Received: 10 June 2008
|
|
|
|
|
|
[1]金学松，沈志云.轮轨滚动接触疲劳问题研究的最新进 展[J].铁道学报，2001,23(2) :92-108
[2]卢祖文.高速铁路轨道技术综述[J].铁道工程学报， 2007(1):41-54.
[3]Anders Ekberg, Elena Kabo. Fatigue of railway wheels and rails under rolling contact and thermal loading-an overview [J]. Wear,2005(258):1288-1300.
[4]刘建锋，魏庆朝.高速铁路钢轨疲劳寿命预测[J].铁道 工程学报，2000(2):30-34.
[5]刘启跃，王夏秋，周仲荣.钢轨表面波浪形磨损研究[J]. 摩擦学学报，1998,18(4) :337-340.
[6]D W Barke, W K Chiu. A review of the effects of out-of- round wheels on track and vehicle components [J].Journal of Rail and Rapid Transit ,2005 ( 219 ) :151-175.
[7]Jones W.Ringsberg. Life prediction of rolling contact fatigue crack initiation[J]. International Journal of Fatigue,23 (2001):575-586.
[8]A. Bemasconi,P. Davoli,M. Filippini,S. Foletti. An integrat- ed approach to rolling contact sub-surface fatigue assess- ment of railway wheels[J]. Wear,2005(258):973-980.
[9]刘启跃，张波，周仲荣.铁路钢轨损伤机理研究[J].中 国机械工程,2002,13(1B):1596-1599.
[10]刘启跃，张波，周仲荣，等.滚动轮波形磨损实验研究 [J]，摩擦学学报，2003,23(2) :132-135.
[11]赵雪芹.钢轨接触疲劳裂纹形成机理研究[D].成都: 西南交通大学，2007.
[12]王文健，刘启跃.PD3和U71 Mn钢轨钢疲劳裂纹扩展速 率研究[J].机械强度，2007,29(6):1026-1029.
|
|
|
|
2008, Vol. 25 
