Plate Assembly Elastoplastic Interactive Buckling Analyses of H Section Steel Members under Compression and Bending

Abstract:

The finite element analysis model of a welded H section steel member subjected to vertical axial compressive force and horizontal load is created to simulate the plate assembly elastoplastic interactive buckling behavior. A series of nonlinear finite element analyses for nonplastic section members with different axial compression ratio, flange widththickness ratio, web heightthickness ratio and flangeweb thickness ratio are performed to evaluate the ultimate moment ratio due to elastoplastic local interactive buckling. A number of correlation curves of ultimate moment ratio versus aforementioned parameters demonstrate that the ultimate moment ratio decreases significantly with increased axial compression ratio and flange widththickness ratio. The normalized fitting formula of ultimate moment ratio is achieved with high accuracy. The allowable widththickness ratio correlation curves are derived on the basis of the principle of simultaneous overall and local interactive buckling. The flange and web widththickness ratio limitations given in the Code for Design of Steel Structures may exceed the parameter regions enclosed by the allowable widththickness ratio correlation curves under certain conditions.