The Effect To Stability Of Steel Members By Bracing Location

In the 《Code for Design of Steel structure》 (GB50017-2003) and 《Technical Specification for Steel Structure of Light-weight Buildings with Gabled Frames》 (CECS 102: 2002) for steel members including steel beams and steel columns, to keep their overall stable it is to use the lateral bracing located in compressed flange. When designing the rigid frame, the calculated length out of plane is the distance between the lateral bracing with maintains overall out of plane stability of the members, and the bracing is set on compressed flange and is valid. But in fact the bracing can not be guaranteed to be set on compressed flanges owing to structural and construction conditions. This case has not been studied and the design method is not available. This main objective of this thesis is to determine the effect to stability of steel members when the bracing is set on different locations of the member section.In this thesis the FEM is used to analyze the nonlinear and elasticity-plasticity characteristic of typical axis-symmetry I-section steel beam under different loads, including concentrated load, uniformly-distributed load and uniform moment. By analyzing the relations of the bracing locations and overall stability coefficient, the bracing efficient coefficient a_e is presented in this thesis which explains the efficiency of bracing at differentpositions. In the end, the relative formulas are given.Through the study in this thesis it is hoped to improve stability theory of steel members and offer a reference to the calculation of buckling strength of steel members with lateral bracing.