考虑钢索松弛的索杆张力结构长期时变性能研究OA

Cable-strut structures in large-span spatial structures typically require ultra-long service life considerations in design.To explore their long-term time-dependent performance considering cable relaxation,theoretical studies were conducted on structural time-dependent theory and structural time-dependent performance analysis methods.Within this theory,time-dependent hypotheses for components and structures were proposed,and time-domain equilibrium equations and stiffness matrix were derived.Additionally,a time-domain analysis method(LM-QN-t)based on the Levenberg-Marquadt and quasi-Newton(LM-QN)iterative algorithm was developed,which was applied to a Geiger cable dome to analyze its long-term time-dependent performance.Results show that the structural time-dependent theory can describe the long-term behavior of such structures considering cable relaxation,and the LM-QN-t effectively enables analysis of this behavior.Calculations indicate that under 1.2 kN/m2 load,the Geiger dome's cable stress decreases by 1%-6%at 50 years compared to initial values,with a maximum node Z-displacement change rate of 15.75%.Some cables'relaxation rates peak in the 2nd year,showing similar patterns under 0.6-1.2 kN/m2 loads.This underscores the significance of studying long-term time-dependent performance of cable-strut structures with consideration of cable relaxation.