Research on the Nonlinear Stability of the Steel Spatial Arch Truss with 120 m Span and 0.2 Rise-span Ratio

摘要

The elasto-plastic stability analysis on the steel spatial arch truss with 120 m span and 0.2 rise-span ratio is carried out with the finite element program ANSYS. In the analyses, two conditions which are the geometric and material nonlinear, double nonlinear under different initial geometric defects are considered. The results show that the instability modes of arch trusses are all asymmetric instability of plane, and that the buckling load and plastic development of the four arch trusses with L/500, L/400, L/300 and L/200 initial geometric defects are decreased with the increase of different initial geometric defects, and that the axial stress of all web members is about the same, but the value of which does not exceed 235 Mpa.