The Vertical Damping Analysis Of Footbridge’s TMD Under The Pedestrian Load

With high-strength materials, new structure, new construction technology widely used, and the improvement of the appeal form of bridge aesthetics, modern pedestrian bridge strides greatly to light quality, long-span and soft. At the same time, with some problems being carried out, the pedestrian bridge can be easily triggered a sharp vibration under pedestrian excitation, which attracted widely attention. The current understanding of pedestrian lateral load on the bridge is primary, with the development of modern structural analysis method, the calculation methods of dynamic analysis of the pedestrian load will be improved and perfect.The using of tuned mass damper(TMD) vibration is a good way to solve excessive vertical vibration problem caused by pedestrians. With an example of a pedestrian bridge, this paper studies the vibration reduction mechanism and damping effect of TMD, the main work is as follows:First, by reading literature and technical information home and abroad, the current national standards of evaluation Pedestrian vibration comfort method are analyzed. The pedestrian excitation load and comfort evaluation index were developed.Second, by using three-dimensional dynamic finite element method and software MIDAS CIVIL, the vibration characteristics of the junction of Pedestrian bridge were analyzed to grasp the basic form vibration.Third, this paper calculates the first vibration response of the pedestrian bridge-TMD in the light of the SDOF structure-TMD model. under the selected pedestrian load condition, and determine damping effect of the bridge by comparing the dynamic analysis results with that of bridges which do not use the TMD.Fourth, contrast the damping effects of STMD and MTMD, and evaluate the advantages of MTMD.Fifth, contrast the vibration control effects of the MTMD designed and the MTMD-1 designed with different calculation methods, and evaluate the advantages and disadvantages of the two methods.The paper supply a way and routing of research for this kind of problem of pedestrian bridge, and give a general thought about the methods of preventing and solving this kind of problem.