The Basic Theoretical Study Of H-section Axial Compressed Steel Member In Confined Buckling

Buckling of steel members is the most important problem for some characteristic of the steels, such as its lightweight, high strength and good mechanical capability, which make the members so spindly. To increase the buckling load, construction measure or control theory is used for confining the buckling of structures in this paper based on traditional buckling analysis. Confined buckling means that the buckling configuration of structures can not be evolved freely due to the presence of the external obstacles. Therefore the final buckling of the members differs very from the case of no external obstacles, and the presence of the external obstacles will change the characteristic of buckling of structures, especially the classical bifurcation diagram. So the key position of the SRC structures can be filled by concrete in appropriate length to change its section dimension, stiffness and deformation curve, the final motive is to increase buckling load by confining buckling of structures.Firstly, buckling load of H-section axial pressure structures is studied aim at two different conditions of support: both ends are hinged and one end is hinged but the other is rigid connection. Factors which influence the section stiffness after filled appropriate length concrete are found in this paper. Then offered mechanics modes and calculational methods in order to analyze the buckling load of the structures under two different support conditions, the method of Rayleigh-Ritz is carried out to gain the buckling load and deformation curve of the members hinged on both ends and finite element method is used for gaining that of the members which are hinged on one end but have a rigid connection on other end.Then by using the eigen-buckling analysis of ANSYS, buckling load of the members in two different supports is calculated, and the results are compared with those of the theory analysis to gain reasonable academic formula.Finial results show that the buckling load can be changed in influence of the filled concrete length and stiffness after filled certain length concrete mainly, and the buckling load can be satisfied by changing them in a certain range.