Prestress Self-Equilibrium Force-Finding Method for Cable-Supported Grid Structures Considering Zero-Stress State Form-Finding and the Construction Process

Abstract

The cable-supported grid structure (CSGS) is a hybrid structure combined with rigidity and flexibility. Its formed state is closely related to the zero-stress state, construction process, and prestress distribution. The prestress self-equilibrium force-finding method is proposed in this paper to continuously conduct zero-stress state form-finding, the construction process, and prestress state force-finding analysis. As the first engineering project adapting CSGS with an internal compression ring, Shanghai Pudong Football Stadium was taken as the analysis object. The structural finite element model was established in ANSYS, structural components were divided into prestress and ordinary components to form a prestress self-equilibrium system, and the equivalent temperature difference was applied to the prestress components as prestress. The Newton–Raphson method was used for geometric nonlinear analysis. The analysis results show that the internal forces and displacements of the formed structure are consistent with the design state, which proves the validity of the method and provides significant guidance for the actual construction. The method proposed in this paper can effectively and accurately obtain the zero-stress state configuration, structural response during construction, and the prestress distribution after forming in a single analysis, without analyzing the above three separately, which improves the analysis efficiency.