Analysis Of Dynamic Response Of Steel Pedestrian Bridge Under Vehicle Load

With the constant development of the city traffic of our country, the steel pedestrian bridge of more and more leap roads appear in the city, function of motive force when these overpasses often receive the passing road to the vehicle. Domestic have not researcher carry on research on vibration impact on overpass that vehicle produce at the passing road seldom at present. These influences including to structure performance influence and to pedestrian comfort level influence. Large span steel pedestrian bridge, Vehicle loads under the pedestrian bridge make many low oscillation amplitude but long durative vibration, which influences the safety and normal usage of the structure. In addition, the structure vibration may beyond the comfort level limit of the human body and makes the pedestrian feel panic when he is on the overpass. Installing Tuned mass damper (TMD)on the steel pedestrian overpasses can effectively reduce the structure vibration , and meet the request of comfort level. This article takes a 46-meter span steel pedestrian overpasse for example, using the finite element method, has analyzed the steel structure reflection under the vehicle loads. adopt finite element method analyze vehicle load, carry on dynamic characteristics analysis and dynamic time history analysis to steel-structured overpass, and through taking the installation measure of TMD, improve the structural performance of the steel-structured overpass and comfortable level of the human body. The main research content includes:1. Introduce the foreign research results of main theory regarding it cause vibration of ground that the road traffic load at present specifically, analyze traffic influence factor, spread law, intensity produced to load distribute law and and brief to introduce vehicle vibrant analysis general method,etc., offer basis on which the following motive force is analyzed.2. Selected finite element software ANSYS, using spatial beam unit Beam188 and elastic shell unit Shell63 established the accurate finite element model, and has studied the basic vibration problem of bridge structure: Bridge dynamic performance.3. Using the transient state analytic method to carry on the dynamic time interval response analysis of the steel pedstrain bridges.It analyzed the stress,displacement,velecity,acceleration of the pedestrian overpass under the vehicles loads before and after the installation of TMD, then compared with the result, in order to make sure the effect of decreasing vibration of the structure which installed the TMD.4. Finally, it gave the methods of the pedestrian overpasses bridge comfort level assessment, then generally compared the control results of comfort level of the bridge whether the structure installed TMD or not.