Research And Analysis Of Steel Truss Footbridge Induced Vibration

In the rapid development of the urban traffic, steel truss pedestrian bridge is a common adopted bridge type, but there have effect of people lead to the vibration.This paper taking a certain steel truss pedestrian bridge as an example with a series of research and calculation, the bridge use steel truss structure. Through the Midas software construct a three dimensional full bridge model calculation and analysis, use of bolt connection and all welding two construction technology, calculated respectively using truss element and beam element, analysis of the respective mechanical characteristics, the modal frequencies of the cause and effect of vibration.Based on this reason to research of steel truss footbridge people caused vibration problem. Details are as follows:(1) For pedestrian bridge situation understanding, of the existing research results, the various countries’research rules as well as the insufficient knowledge of study;(2) According to the high of the beam, beam breadth, and cross the change of section height and width, calculation and analysis of steel truss pedestrian bridge frequency change and for people to vibration. Draw curve of beam, beam width as well as the cross-section height of bridge vertical frequency and lateral frequency, Get a series of conclusions thebigger high beam lateral greater the frequency, the smaller the vertical frequency;(3) For this kind of steel truss pedestrian bridge of lateral people cause vibration, we adopt single lateral people cause vibration and the crowd lateral people cause vibration calculation and analysis, including slowly walking, normal walking, fast walking, normal run, fast run5kinds of moving load conditions lateral people cause vibration calculation and analysis, get the different load conditions curve of displacement and acceleration, Close to the lateral bridge frequency gallop generated displacement and acceleration is greatest. The crowd, use of the latest German standard EN03, according to the relative comfort index decision the comfort of this bridge, The comfort of this bridge belongs to the relatively poor range;(4) According to the self-excited vibration theory, use Dallard load model and the calculation formula of Newland respectively get the bridge lateral dynamic buckling critical number;(5) In the pedestrian incentive calculation, This bridge resonant acceleration response belonging to poor range, it cited the introduction of a variety of damping, and finally the use of the TMD damping settings, energy consumption and the effect is obvious;(6) Concrete pedestrian bridge modal analysis, each mode shape and frequency of the bridge, and draw concrete bridge is to avoid the footbridge people caused the vibration is a better choice.