Due to extensitve application of bridge structure on high speed railway line, it is necessary to consider comprehensively the common effect of the train, the track and the bridge. By forming an integrated large system...Due to extensitve application of bridge structure on high speed railway line, it is necessary to consider comprehensively the common effect of the train, the track and the bridge. By forming an integrated large system including the car and locomotive system, track system, bridge structure system and making use the interaction of the wheel/rail as the ″link″ between these systems, the study focuses on the coupling dynamic analysis of the train, the track and the bridge. Based on the summary and digestion of the predecessor′s research experiences, this article studies the coupling vibration of the train, the track and the bridge structure system on the high speed railway line. It covers the following: 1. Establishment of a more completed dynamic analysis model for cars and locomotives: the four axle car with two level suspension is used for the study and a space vibration analysis model constituting of such rigid bodies as carbody, bogie frame and wheelset is built. There are totally 31 degree of freedom, i e, 5 for the carbody and the front and rear bogie respectively, including horizontal movement, bounce, roll, pitch and yaw, 4 for each wheelset, including horizontal movement, bounce, roll and yaw. In the wheelset movement equation, the previous assumption that the wheelset always keep rigid contact with track in the car bridge coupling analysis has been corrected. The wheelset is allowed to leave the track, i e, ″jump on rail″. The degree of freedom of the wheelset has increased from horizontal movement and yaw, 2 in total, to horizontal movement, bounce, roll, and yaw, 4 in total. The degree of freedom for the car model has increased from 23 to 31. 2.Establishment of track structure dynamic analysis model of the multi layer supporting system aiming at ballasted track bridge of multiple spans for the first time: in accordance with the type and characteristics of different track structure and their models and aiming at the most common used ballasted track, the study selected the continuous elastic Eule展开更多
In this work, we study the coupled cross-flow and in-line vortex-induced vibration （VIV） of a fixedly mounted flexible pipe, which is free to move in cross-flow （ Y- ） and in-line （ X- ） direction in a fluid flo...In this work, we study the coupled cross-flow and in-line vortex-induced vibration （VIV） of a fixedly mounted flexible pipe, which is free to move in cross-flow （ Y- ） and in-line （ X- ） direction in a fluid flow where the mass and natural frequencies are precisely the same in both X- and Y-direction. The fluid speed varies from low to high with the corresponding vortex shedding frequency varying from below the first natural frequency to above the second natural frequency of the flexible pipe. Particular emphasis was placed on the investigation of the relationship between in-line and cross-flow vibration. The experimental results analyzed by using these measurements exhibits several valuable features.展开更多
文摘Due to extensitve application of bridge structure on high speed railway line, it is necessary to consider comprehensively the common effect of the train, the track and the bridge. By forming an integrated large system including the car and locomotive system, track system, bridge structure system and making use the interaction of the wheel/rail as the ″link″ between these systems, the study focuses on the coupling dynamic analysis of the train, the track and the bridge. Based on the summary and digestion of the predecessor′s research experiences, this article studies the coupling vibration of the train, the track and the bridge structure system on the high speed railway line. It covers the following: 1. Establishment of a more completed dynamic analysis model for cars and locomotives: the four axle car with two level suspension is used for the study and a space vibration analysis model constituting of such rigid bodies as carbody, bogie frame and wheelset is built. There are totally 31 degree of freedom, i e, 5 for the carbody and the front and rear bogie respectively, including horizontal movement, bounce, roll, pitch and yaw, 4 for each wheelset, including horizontal movement, bounce, roll and yaw. In the wheelset movement equation, the previous assumption that the wheelset always keep rigid contact with track in the car bridge coupling analysis has been corrected. The wheelset is allowed to leave the track, i e, ″jump on rail″. The degree of freedom of the wheelset has increased from horizontal movement and yaw, 2 in total, to horizontal movement, bounce, roll, and yaw, 4 in total. The degree of freedom for the car model has increased from 23 to 31. 2.Establishment of track structure dynamic analysis model of the multi layer supporting system aiming at ballasted track bridge of multiple spans for the first time: in accordance with the type and characteristics of different track structure and their models and aiming at the most common used ballasted track, the study selected the continuous elastic Eule
基金This project was financially supported by the High Technology Research and Developmant Programof China (GrantNo.2006AA09Z356) the National Natural Science Foundation of China (Grant No.503795)
文摘In this work, we study the coupled cross-flow and in-line vortex-induced vibration （VIV） of a fixedly mounted flexible pipe, which is free to move in cross-flow （ Y- ） and in-line （ X- ） direction in a fluid flow where the mass and natural frequencies are precisely the same in both X- and Y-direction. The fluid speed varies from low to high with the corresponding vortex shedding frequency varying from below the first natural frequency to above the second natural frequency of the flexible pipe. Particular emphasis was placed on the investigation of the relationship between in-line and cross-flow vibration. The experimental results analyzed by using these measurements exhibits several valuable features.
