Stability Research Of Steel Beams With Lateral Elastic Brace

Buckling of steel beam is the most important problem for designing of steel structure.Once buckling appeared in compressed member,flexural member or shear member, structureimmediately collapsed, so the stability problem is more important than strength problem.Although the stability problem has been vast researched and made great achievements in thepast hundreds of years, but because of the complexity of stability problem, the research ofthis aspect is still on.However,buckling of steel beam can be prevented by lateral or torsional braces. In orderto improve the stability of steel beam, this paper adopt to set lateral elastic brace in midspanof double-span beam and cantilever beam ends. Because of the research on the bucklingbehaviors of steel beam with lateral elastic brace is very little,the purpose of this paper is toimprove and develop the existing theories, which is based on continuous model, using theenergy variational method give some complex analytical solution of the problem, at the sametime give the corresponding high accuracy of numerical solution; at the same time using thefinite element model for calculation and analysis, application of theory and finite elementsimulation method, the data which abtained is ture and reliable, and provide a basis for followstudy and establish the foundation formula for the pratical project.This paper adopt to a method that the theory is combined with numerical simulation. Itconsists of two parts as follows：1. the theory analysis on the stability problem of steel beam with lateral elastic braceBased on the existing of the total potential energy expression,separately analyzed theproblems of buckling,such as double-span beam with lateral elastic brace under concentratedload,cantilever beam with lateral elastic brace under concentrated load and uniform load.This paper is based on the principle of minimum potential energy give high-precisionnumerical solution by using the energy variational method and introducing of dimensionlessparameters. Obtained the high-precision and reliable formula by substantial calculating forcalculating the critical buckling moment.2. the finite element analysis on the stability problem of steel beam with lateral elasticbraceFirstly, using the existing literature to verify the finite element model,and then select twokinds of GB H-shaped steel section to stablish finite lement model.and verifing the theoreticalsolution of this paper through finite element analysis.