不同连接强度带悬臂梁段的钢框架结构滞回性能研究

An experimental study of a different-connection-strength column-tree moment-resisting frame structure

为了研究利用钢梁高强度螺栓拼接耗能的带悬臂梁段钢框架结构的滞回性能,按照不同的设计方法,设计了3个带悬臂梁段上下各半层的钢框架试件并进行循环加载试验,分析试验现象,研究其滞回性能、应变分布、转动能力、能量耗散系数、刚度等参数。通过对比分析表明:等强拼接方法设计的钢框架刚度大,延性较差,在梁端处形成塑性铰,梁端焊缝处易开裂;削弱拼接节点,使高强度螺栓提前滑移,增强了钢框架的延性和转动能力,延缓了梁端板件的屈服,降低了整个框架的屈服荷载,钢框架的极限荷载不受影响;实际内力值方法设计的带悬臂梁段钢框架结构抗震性能最好,建议按此方法设计带悬臂梁段钢框架结构中的钢梁拼接节点,并将拼接节点尽量靠近梁端设置。

This work aims to study the seismic performance of a column-tree moment-resisting frame structure with beam splice joints using high strength bolts. According to different design methods, three half-story column-tree moment-resisting frame specimens were designed and tested under cyclic loading. Hysteretic behavior, strain distribution, rotation capacity, energy of dissipation factor, and stiffness were studied according to analysis of experimental phenomena. Comparative analysis shows that steel frame designing using equal strength method has large rigidity and poor ductility. Plastic hinge forms at beam end. Cacks may develop at beam-to column welding joint. The phenomenon of high strength bolt sliding appeared early in frame with weakened splice joints. Steel frame ductility and rotation capacity were improved. The yielding at beam end was delayed. Yield load was decreased but ultimate load carry capacity was not affected. The seismic performance of column-tree moment-resisting frame structure designed using actual internal force method is the best. Based on these results, proposal of designing beam splicing joints of column-tree moment-resisting frame structures using actual internal force and setting the location of splice joint near to beam-to column welding was provided.