Study On Vibrations Of Floor System Of Through Truss Bridge Excited By Moving Train

In recent years, because of the increase of speed of trains, the increase of vehicle load and the birth and rapid development of high-speed train, dynamic interaction in the train-track-bridge becomes more prominent. So more consideration should be put on the floor systems, also the request should be more rigorous. In the era of rapid development of science and technology today, the applicability of traditional static and quasi static design method cannot meet the needs of the practical application of modern bridge structure essentially. Therefore, to meet the need of modern science and technology design, the existing railway floor systems of truss bridge should be optimizing designed and be safety evaluated by using the knowledge of modern dynamics theory and advanced technology.The technology development of railway truss bridge home and abroad and the dynamic research of railway-bridge are reviewed in this paper simply. On the basis of the existing status of dynamic interaction of train-track-bridge the train, track and floor systems as a system is put forward which aim at the bridge’s vibration of existing line strain. Regarding the relation of the interaction of track and bridge as the connection link of the whole system, study on spacial dynamic characteristic of train, pillow rail and floor systems.The system model and motion equation of train, pillow rail and floor systems are established in this paper. Newmark-β integral method is used to solve space vibration equations of vehicle-pillow rail-floor systems. And the motion equations of ballastless track are analyzed. Then we adopt Ritz method to transfer the orbit partial differential to ordinary differential equations. And the orbit of steady-state vibration under resonant force is solved. Regarding the track irregularities and wheel for sinusoidal as excitation source, with the equal effects method of frequency domain power spectrum, the railway Low-interference numerical computation is made.Beijing-Shanghai railway bridge of Huaihe is considered as the engineering example in this paper, and driving vibration of floor systems of simply supported beam truss bridge is analysed. The changing rules of the dynamic response of train-railway-floor systems are researched under different speeds and some irregularity level. Vibration response is obtained about train, trick and bridge deck system and so on. Then their relations are discussed preliminarily. And the corresponding conclusions are obtained.