Study On Dynamic Characteristics Of Long-Span Suspension Bridge And Its Parametric Analysis

Long-span bridge is a type of cable rope structure which has strong nonlinear influence and large flexibility. It has high dynamic response under the earthquake load, wine load, vehicular load and other dynamic motivation. Therefore,the dynamic response is certainly one of committed steps control the structural design. Before doing analyse the performance of suspension bridge under dynamic force, it has to determine the line shape and stress condition of the bridge, that is vastly different form any other type of bridge. In this paper, yangluo changjiang river bridge in wuhan is taken as the background, .circling round the analysis of dynamic characteristics of long-span suspension bridge, some significant study is carried out.Based on the segmental catenary theory ,the iteration format is established under the dead load state of suspension bridge ,meanwhile the revision analysis of cable shape round the saddle is also carried through, at last a program which is by analysis is developed to calculate the cable shape under the dead load state of suspension bridge A finite-element method based on ANSYS is supplied to determine the dead load state of suspension bridge, which is through adjusting the initial strain of main cable , bearer cable and bridge tower. later, the spatial model which is used to the analysis of dynamic characteristics is built. Two different condition, one is considering the soil-pile-structure influence while the other is not, are provided to calculate the dynamic characteristics, then the comparison is done between the two different condition.Parametric analysis of dynamics characteristics is done through changing the structure parameter and material parameter, such as structural stiffness, the weight of beam, ratio of rise to spanned and so on. Regular patterns of dynamic characteristics is obtained through parametric variation..Using inverse dismantling calculation, the method of determination of erection-parameters is got form dead load state. This paper took the engineering as the example, the common software ANSYS is used to simulate the course of construct. Then the cable shape of main cable and its stress state is got in each construct stage, also with the vertical-longitudinal mode. After that, corresponding spatial models in some construction stage are built for mode analysis.