Simulation Study on Stability of Half-Through Steel Truss Girder

: In order to discuss and analyze the simplified calculation model and influence factors of external stability of half-through steel truss girder. 56 m half-through railway steel truss girder was set as a study object. Its 3-D whole model was build with finite element software ANSYS. The linear stability coefficient and the buckling mode under different load conditions were analyzed. The results show: The buckling curves under all conditions present as that external buckling of upper chord. According to the structural features and buckling features of half-through steel truss girder, the whole model was simplified as plane model. It was composed of semi-frame and upper chord with lateral elastic bearings, and the calculating steps in external stability analysis are given. On the basis of simple plane model, the parameter effect analysis of external stability of half-through steel truss girder was conducted with finite element method. The influence law of the high, the width of main truss and area of wind brace on lateral displacement of semi-frame, lateral stiffness of upper chord and overall structural stability coefficient. The results show: increasing the high of main truss, decreasing the width of main truss and installing wind brace all can effectively improved stability.