Research Of Suspender Tensile Force Optimization For Special Shape Concrete-Filled Steel Tubular Arch Bridge

Concrete-filled steel tubular arch bridge has been soon applied and developed in our country in recent years, and now has come in long-spans and nearly competed in very long spans for five hundred meters, used in bridge construction project not only in the locations where bridges crossing rivers but also crossing seas. On the following study in-depth of the deformation mechanism of beam-arch association bridge, the author of this paper programmed by APDL(the scondary development of ANSYS),utilized the optimization analysis functions of the popular FEM software-ANSYS, and gave a practical method on how to get the best suspender tensile forces of concrete-filled seel tubular arch bridge, also gave the relationship of the suspender tensile forces and the inner force of the arch.1,practial formula of the beam-arch association bridgethe deformation mechanism of beam-arch association bridge was described:the paper assumed the all the suspender tensile forces were equal, and the suspender tensile forces could be regarded as filmy ones.The beam-arch association bridge was departed into beam-arch body and filmy suspender. Through the deforming balance equation at the midpoint, the practial formulas of filmy suspender tensile forces, deflection at the midpoint were acquired. There was another way to the formulas of dynamic deformation balance equation.2,Valuating (optimizing) of suspender tensile forcesOn the analysis of horizontal and vertical according to the assumptions of practical calculation, the author got some conclusion which was useful in the subsequent optimization calculation. A new method to valuate the suspender tensile forces for spatial multisuspenders was presented, which was based on the optimization algorithm in the popular FEM software-ANSYS, could ensure that the rationality of internal force and line shape was completely emulated, and was convenient to deal with all thenonlinear factors. The method is simple and feasible, and can set up the direct and forward connention between the suspender tensile forces (design variables) and indexes of rational design point.3,The relative size of the suspender tensile forces and relationship between suspender tensile forces and inner force of archThe author converted the structure into a planar one, calculated the suspender tensile forces again using the method the paper gave, analyzed the relative size of the suspende tensile forces. The author also gave the mechanics relationship between suspender tensile forces and inner force of arch as the preliminary theoretical basis of the assumption used in the paper.