橋樑結構與高速列車之動力互制三維模擬分析

• Main Author: 王涵忠
• Other Authors: 丁承先
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/18569334611569047167

碩士 === 國立中央大學 === 土木工程研究所 === 89 === Abstract The dynamic response of a bridge structure due to traveling vehicles has long been a subject of intensive research in engineering. In Taiwan, the project of a high-speed railway system in the west corridor between Taipei and Kaohsiung is under construction. A special feature of the Taiwan high-speed railway is that the elevated bridges have been adopted as the major supporting structures for over 70 percent of the railway lines. Thus, the problem of train-bridge interaction has become an important issue. In the majority of reported studies for the vehicle structure interaction, the basic method of analysis is solving a set of partial differential equation. In the formulation, simplified vehicle models are assumed. For a low-speed railway system, the vehicle can often be represented as a set of concentrated forces, and the track structure on the bridge can be ignored. For high-speed trains, it is necessary to consider the vehicle as a set of mass particles to include the heaving inertia of the train. The analyses based on simplified vehicle and structural models clearly do not simulate the realistic responses of the system. In this study, we adopted a direct numerical approach. In the model, three sub-system, the vehicle, the bridge structure, and the dynamic interaction, and formulated separately. Compatibility and equilibrium conditions link them together. For the interaction model, an integral equation is used. Neglecting the actions of railpads and sleepers, the track structure can be simplified as an infinite, continuous rail lying on a single-layer ballast foundation and bridge as a simply supported beam. A realistic three-dimensional modeling of the high-speed train by using a set of multiple rigid bodies is also developed. Classical approach often assumes a single train moving at constant speed. In this study, it is possible to consider different combination of train operations, including following trains and trains crossing one another. The result shows that our approach can be accurate in computing both the vehicle and bridge responses, especially in high speed. In comparison with the traditional partial differential form, the integral formulation eliminates the high-order spatial derivatives, the Delta functions and explicit boundary conditions. Thus, the numerical approach has the advantages of considering complicated vehicle and structural models. It is interesting to note that if the response of the sprung body has been taken as a measure of the passenger’s riding comfort, our study shows that the vibration period of the train body increases as the traversing speed increases. This indicates that the motion of a high-speed train is smoother than a low-speed one.