Study On Stability Of Q345GJ Steel Axial Compressed H-shaped Members

As a kind of high performance material for super high-rise buildings and long span structures, GJ Steel has much better properties compared with high strength low alloy steel. So for, GJ Steel has been used in national Olympic stadiums, Beijing Capital Airport, CCTV Building and other important constructions.It is based on previous analysis results on property parameters of Q345GJ Steel. This dissertation describes the experimental and the ANSYS finite element analysis study on the ultimate strength of Q345GJ Steel H-shaped axial compressed members. On the experimental study, fundamental mechanical performance of the experimental material in three different plate thicknesses, 16mm, 25mm, 35mm are tested. In addition, residual stress test, short columns test and long columns test of two types of H-shaped members, H350x250x16x35 and H350x250x16x25 are stuied. Study on emphasis of long columns test is the buckling behaviour of weak axis.Taking into account distribution of residual stress and initial geometric imperfection, the axial compressed members of two cross sections corresponding buckling patterns, bucking strength and loading-placement curves are obtained trough the ANSYS finite element analysis study. It is the foundation of the further development of the global stability study of GJ steel.Trough the ANSYS finite element analysis study, comparison of stability coefficient of GJ steel axial compressed H-shaped members and current codes, the former stability coefficient is greater about 30% than the latter one after verifying validity of the ANSYS finite element models based on a series of experimental study and analysis. It must be studied further for the effective utilization of the GJsteel to obtain the column curves. This project is to lay a solid foundation for application of GJ Steel in steel constructions.