Optimum design for truss and string structures: Fid-Bau Portal

Optimum design for truss and string structures

Jiansheng Zhang, / Diansheng Zhao, / Guangen Zhou,

In order to determine the optimized parameters and offer logical advice for the design of truss and string structure, systematic parametric analysis for the mechanical behavior of the structure have been performed using ANSYS finite element software. Based on the discussion of effect with different factors, including ratio of string height to structural span, ratio of arch height to structural span, pre-tension value of the string, size of the truss, the optimized parameters for the design of truss and string structure are obtained.The results indicate that: (1) The ratio of string height to structural span (expressed as f₁ /L), and ratio of arch height to structural span (expressed as f₂ /L), are the most important factors influencing the mechanical behavior of the structure. The appropriate range of these two parameters is 0.05-0.1 for f₁ /L and 0.05-0.125 for f₂ /L respectively. (2) The pre-tension value of the string depends on the structural span, and the appropriate range of this parameter is 1200kN~1400kN for the truss and string structure whose span is 110m. Moreover, the pre-tension value of the string would increase 200KN when the structural span increases 10m. (3) There is very little effect of the size of the truss for the mechanical behavior of the structure.