Semi-analytical Analysis Of Curved Tubular Structural System With Curved Side

The static and free vibration analysis as well as structure-foundation-soil interactions of curved tubular structures were studied and analyzed with a multi-dimensional model by means of ODE Solver (Ordinary Differential Equation Solver). The principal work performed by the thesis can be summarized as follows:1. Based on the principles of equivalent stiffness and mass, a curved tubular structure is simplified as a thin-walled curved tube of variable cross sections supported on a semi elastic body, then a semi-discretization is made by some longitudinal nodal lines on the model, and the unknown deformation functions defined on the longitudinal node lines are used as primary unknown functions so as to describe the displacement field or the motion field of the curved tubular structural system ; According to the minimum potential energy principle and the Hamilton principle, the differential equations and their corresponding boundary conditions that controlling the static and free vibration of the equivalent continuous model were derived, then the static and structural dynamic problems were investigated to the boundary value problems or eigenvalue problems of ordinary differential equations, then the equations were solved by utilizing Ordinary Differential Equation Solver(such as COLSYS).2. Interactions between the subgrade and the foundation and the curved tubular structures have been analyzed through numerical examples, and the free vibration analysis for the curved tubular structures with thin-walled cross sections are also performed by the semi-analytical method based on Ordinary Differential Equation Solver. Some conclusions are obtained, such as a curved tubular structure has great structural integrity; the natural periods of the curved tubular structure will vary with the relation of the ground-foundation-superstructure stiffness.Some reasonable conclusions were also obtained from the modeling and the result of computed examples. Therefore a sort of quick and simplified analytical method suite for the preliminary design and global behavior evaluation of curved tubular structural systems for tall buildings was presented.