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Study on path prediction of spalling defect on rail surface |
Received:January 10, 2021 Revised:February 07, 2021 |
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DOI:10.7511/jslx20210101001 |
KeyWord:rail spalling defect stress intensity factor maximum circumferential stress criterion propagation path |
Author | Institution |
孟睿君 |
郑州工业应用技术学院 建筑工程学院, 郑州 |
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Abstract: |
Under the wheel/rail rolling contact force,the rail surface will produce typical fishhook shaped spalling defect,and its formation mechanism is not clear at present.In order to explore the propagation mechanism of rail surface cracks under the wheel/rail rolling contact force,the fatigue calculation model of wheel/rail rolling contact was established and the prediction method of crack propagation path was proposed based on the maximum circumferential stress criterion.The results show that,the surface microcracks of the rail belong to the I-II mixed cracks.With the increase of crack length,the stress intensity factor KI increases firstly and then decreases.However,the KII shows a trend of continuous increase.When the crack grows to a certain depth,the driving force of crack propagation changes from KI to KII.At this point,the crack tip will turn about 70° under the drive of KII,and tends to propagate upward and leads to fishhook shaped spalling defect.The angle of initial crack on rail surface has an obvious influence on the path of the spalling defect,but has little influence on the depth of the spalling defect.The research results of this paper provide a theoretical basis for the formulation of maintenance regulations for rail surface grinding. |
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