隔板贯通式箱型柱-H型钢梁异型节点试验、断裂机理及设计方法研究-结构工程专业论文.docx

万方数据 万方数据 隔板贯通式箱型柱-H 型钢梁异型节点试验、断裂机理及设计方法研究 Study of Experiment, Fracture Mechanism and Design Method on Diaphragm-through Irregular Joints of Steel Box Column and H- section Steel Beam Abstract In this paper, five diaphragm-through irregular joints of steel box column and H-section steel beam with enlarged arc junctures and one conventional irregular joint were tested under low- reversed loading. The effects of enlarged arc junctures on failure mode, bearing capacity, plastic rotation, hysteresis loops, rigidity degradation and energy dissipation of diaphragm-through irregular joints were investigated. The numerical simulation base on the steel ellipsoid fracture model considering welding defects and welding residual stress and coupled ellipsoid yield model of irregular joints was performed. Seismic performance and plasticity developing process of the irregular joints with enlarged arc junctures and conventional irregular joints were studied . Failure mechanism of irregular joints was analyzed. Ductile structural study and design method of irregular joints were put forward. The study results indicate that the conventional irregular joint brittle fractures at butt weld between the flange of stronger beam with large rotation rigidity and diaphragm-through rib, and the plastic rotation of the conventional irregular joint, couldnt match the minimum requirement 0.03 rad in FEMA. For the irregular joints with enlarged arc junctures, the plastic hinge is obviously formed at enlarged section of diaphragm and the plastic rotation reach 0.033~0.044 rad. The bearing capacity and the energy dissipation capacity of the irregular joints with enlarged arc junctures increase by 41.7%~53% and 173%~500%, respectively, compared with that of the conventional irregular joints. The sharp changes and stress concentration near butt weld in the conventional irregular joint are eliminated by using of enlarged arc junctures and moving butt weld to the location far away from the connection zon