Elastic Stability Of Girder Web Panels And Steel Shear Walls Vertically Strengthened By Closed Section Stiffeners

This paper analyzed elastic local buckling of girder web panels and elastic stability of steel shear walls vertically strengthened by closed section stiffeners with FEM, including the following four parts:(1) At first, elastic buckling critical stress of thin rectangular panels in patch loadings is analyzed, taking account of restrained effect of panels in both sides as well, and corresponding formulas are given. Then, this paper analyzed buckling stress correlativity of simply supported plate under combined patch loading and shear, combined patch loading and bending stress, combined shear and bending stress with FEM. Then, correlation formula under each condition is presented, which is adequate for different aspect ratios. Finally, this paper researched buckling of simply supported plate under combined bending, shear and patch loading, and proposed a curved surface of correlation under this condition with sliced method. Compared with the calculated results, the proposed formula has good accuracy.(2)Shear buckling of steel Plate shear walls vertically stiffened by closed form stiffeners is investigated, curves of relating shear buckling stresses to flexural and torsional rigidities of stiffeners are presented. Threshold rigidities of stiffeners determined by the demand that the critical shear stresses be equal to the buckling stress of simply supported sub-panels, are presented. In case that the rigidities of stiffeners are less than the threshold value, a formula is proposed relating the buckling stress to the rigidities of stiffeners. Plates stiffened by one side channels or stiffened by one side channels alternately on both sides of the plate are analyzed and compared with double-sided stiffeners. A modification factor is proposed for the threshold stiffness of one-sided stiffeners.(3) Elastic buckling of steel Plate shear walls vertically stiffened by closed form stiffeners under axial compression is investigated, curves of relating axial compressive buckling stresses to flexural and torsional rigidities of stiffeners are presented. Threshold rigidities of stiffeners determined by the demand that the critical axial compressive stresses be equal to the buckling stress of simply supported sub-panels, are presented. In case that the rigidities of stiffeners are less than the threshold stiffness, a formula is proposed relating the buckling stress to the rigidities of stiffeners. Plates stiffened by one side channels or stiffened by one side channels alternately on both sides of the plate are analyzed and compared with both side stiffeners. Modification factor is proposed for the threshold stiffness.(4) Elastic buckling of steel Plate shear walls vertically stiffened by closed form stiffeners under combined axial compression and shear stress is investigated, and it indicates that its threshold stiffness is related to threshold stiffness in shear, threshold stiffness under axial compression and ratio of width to height. Formulas with high accuracy are proposed too.