Study On The Overall Stability Of Axially Compressed Built-Up Steel Columns With Batten Plate

Many of bridge structures are compression members such as diversified chord members and web members in tuss bridges, diversified stanchiones, piers, high capped pile foundations and pile foundations. Elastic buckling and enelastic-buckling on the overall stability of axially compressed built-up steel columns with batten plate, which are widely used in the steel constructures, are studied in this thesis through theoretical analysis and FEA saparately. The main research aspects are as follows:Firstly, related concepts and calculating methods about the stability problems in steel bridge are introduced in this thesis. Theoretical knowledge and study status quo about elastic buckling and enelastic-buckling of axially compressed member also are expatiated by the numbers. Then the stability of laced built-up compression members is studied.Secondly, the validity of analyzing built-up columns by the general FEA program ANSYS is studied, and many numerical results confirmed the validity of the method. With the programe, the overall elastic stability of many members with different channel steel types, different spaces between channel steel, different batten plate numbers, and different batten plate sizes under different slenderness ratios is analyzed.Finally, considering the effects of geometrical nonlinearity and material nonlinearity, the ultimate carrying capacity of the built-up steel columns with batten plate is studied.