05.42: Evaluation of ultimate strength and plastic deformation capacity of square hollow section members under bending shear

Abstract

ABSTRACTThe purpose of this study is to evaluate ultimate strength and plastic deformation capacity of square hollow section members under bending shear governed by local buckling as a function of member shapes and loading conditions. First, elastic local buckling strength under bending shear derived from theoretical analysis is shown. A new normalized width–thickness ratio SH based on elastic local buckling strength and full plastic strength is proposed. Then, after understanding the elastic local buckling behavior purely determined by member shapes and loading conditions, the large deformation behavior under monotonic bending shear is examined using numerical analysis and structural testing. The ultimate strength and plastic deformation capacity are evaluated using the new normalized width–thickness ratio SH as a function of width–thickness ratio, aspect ratio, gradient of bending moment, and angle of applied force. Finally, the large deformation behavior under cyclic bending shear is examined using structural testing. The relation between the ultimate strength or plastic deformation capacity and the new normalized width–thickness ratio SH is reported.