Dynamic Response Analysis Of Suspension Bridge Under Moving Loads

Suspension bridge structures are characterized by large span, high flexibility, typhoon, earthquake and vehicular load and other dynamic load is more sensitive, which are associated with the structural dynamic characteristics (natural frequency, vibration mode, damping) are inseparable. Suspension bridges under moving load, dynamic response is based on the structural dynamic characteristics analysis of ultimate purpose. Under the action of moving loads suspension bridge dynamic response results not only and the structure of its vibration characteristics, and external load property.This paper takes Nanxi Yangtze River bridge as engineering background, on the single span suspension bridge vibration characteristics are discussed, using the FEM software MIDAS/CIVIL established the spatial mechanics finite element calculation model, analysis of single span suspension bridge dynamic characteristics and stiffness of structure parameters on its influence as well as under moving loads the dynamic response of a bridge and other problems.First of all in the single span suspension bridge based on the analysis of free vibration characteristics of suspension bridge, described as a continuum space coupling free vibration based differential album album called integral equation and the vertical bending vibration and torsional free vibration equations of the process; and the existing fundamental formula for approximate calculation of suspension bridge was briefly evaluated. Secondly, using subspace iterative method to calculate the vibration frequency of the bridge, and analyzes the corresponding vibration characteristics, combined with the calculation results of single span suspension bridge dynamic characteristics are discussed, and then for the single span suspension bridge structural stiffness on the vertical, lateral and torsional vibration frequency was discussed that the effect of. Once in the suspension bridge dynamic characteristics on the basis of the analysis, the bridge subjected to moving vehicle loads the dynamic response is studied and analyzed, calculated and analyzed according to the size of value of the triangular load at different speeds when crossing the bridge structure internal force, displacement and vibration response of the bridge.