Time-domain Vibration Analysis Of Long-span Cable-stayed Bridges Model Structure

As cable-stayed bridges are increasing popularity, more concerns are raised about their seismic behavior. Although several recent investigation have contributed significantly to the earthquake-response analysis and design of long-span cable-stayed bridges, it is still essential that more research be conduced to investigation some aspects of the problem, also there are many problems required to solve about the seismic studies of cable-stayed bridge models. Earthquake analysis for long-span cable-stayed bridges has two aims: the first is to ensure an enough safety margin against basal earthquake intensity; the second is to provide scientific bases and effective ways for vibration resistance design of bridge.To meet this requirement this paper present following studies:1. Similar theory is deduced about long-span bridge model structure. It advanced the foundation of static and dynamic model similar theory of structure experimentation model. And according to the information of the model of Hunan Yueyang Dongtinghu bridge deduced similitude ratio of similitude criterion and mode parameter.2.Based on the FEM analysis of the cable-stayed bridges, the equation of motion of the bridge with M-DOF due to seismic excitation is formulated and then is expressed with the incremental formation. A Fortran program SRBS is described to perform the dynamic analysis. In the program, the differences of the mass matrix are considered between the bridge and its model.3. Structure calculate software is used to analysis the vibration characteristic of cable-staged bridge of Yueyang Dongtinghu bridge and its model. Three cases including ID, 2D and 3D seismic inputs are implemented with the model bridge, with particular emphasis on the effect of geometric on the dynamic behavior of the long-span cable-staged bridge. Several conclusions are drawn from the above study.