Numerical Simulation Method Of Cable-Supported Joint And Dynamic Response Analysis Of Cable-Supported Truss Structure

Cable-supported structure is a kind of brand new and efficient space structure system which has good safety and economy. This new structure is worthy of further study. As a result of the use of continuous stay cable technology, there is friction-sliding of cables at cable-supported joints. The cables don’t support structure by "suspend" or "pull", but "hold". In this way, the behaviors of the whole structure have been changed. Nowadays, there is fewer documents about slideable continuous cable element. Therefore, how to make accurate simulation of cable-supported joints will be a key problem during the design of cable-supported structure. This article talks about numerical simulation method of cable-supported joints in cable-supported structure and discusses the mechanical behavior and seismic capacity of cable-truss structure. The main research content includes:Based on the working platform of ANSYS finite element software, simulation to the whole truss and the analysis of relevant finite elements could be fulfilled. A new numerical simulation of cable-supported joints method, namely invariant stiffness short beam method, was put forward, and the essence of the method was to make use of the flexural rigidity of short beam to simulate the friction at cable-supported joints. According to friction loss and slippage of cable at cable-supported joints, the stiffness of short beam could be confirmed. Moreover, an example analysis and comparison with other three modeling methods of cable-supported joint (free coupling method, free coupling and varied stiffness spring element method, joint-joint contact method) have been made. According to the evaluation to each method, a cable-supported joint numerical simulation method was proposed, which is relative simple and can meet the requirement of project precision. The analysis showed that deflection and difference of component internal force of truss structure raised by the four methods were not very obvious, and the results were basically identical. Free coupling and varied stiffness spring element method and invariant stiffness short beam method could well simulate friction at cable-supported joints and they were relatively ideal numerical simulation methods of cable-supported joints.Then, the static analysis to cable-truss structure was finished separately under full-cross vertical loading and semi-cross vertical loading. The calculated results were compared with truss structure and grid structure. The analysis showed that cable-truss structure had better mechanical behavior, and the loading has been efficiently, evenly and reasonably distributed by flexible cables.Finally, the dynamic response analyses of cable-truss structure were carried out to research the structural response under small earthquake effect, including mode-superposition response spectrum method and time-history analysis method. Besides, calculations were made under effect of horizontal earthquake and vertical earthquake, and a comparison to truss structure and grid structure was made. The analysis showed that cable-supported structure had strong nonlinear characteristics and time-history analysis method should be used for dynamic response analysis of cable-supported structure. Under horizontal earthquake, cable-truss structure had better seismic behavior than truss structure did. However, on the aspect of horizontal stifness, grid structure had better performance than cable-supported structure. Under the effect of vertical earthquake, cable-supported structure had better seismic behavior than truss structure and grid structure.