长圆孔腹板连梁连柱钢框架结构抗震性能研究

RESEARCH ON THE SEISMIC BEHAVIOR OF A LINKED COLUMN STEEL FRAME STRUCTURE WITH SLOTTED HOLE WEBS

耗能连梁是连柱钢框架结构的重要构件,传统耗能连梁在往复荷载下常常出现加劲肋与腹板间焊缝的首先破坏,从而降低了塑性转动能力。为了提高耗能连梁转动能力,并使其尽早进入塑性耗能,可采用长圆孔腹板耗能连梁代替传统的耗能连梁。通过ABAQUS有限元软件分析了配置长圆孔腹板耗能连梁连柱框架结构的滞回性能。分析结果表明:耗能连梁腹板厚度t_w的增加可以提升结构的刚度、承载力以及耗能能力。孔间柱长宽比β越小,结构性能越好,考虑应力集中与钢材初始缺陷,建议设计时β可取1～1. 2。长圆孔腹板耗能连梁长度L的增加可以提升结构耗能性能,但L过长时,塑性发展不充分,不能充分发挥材料性能,宜取主结构跨度的16%～22%。提升框架钢材等级可以显著提升结构的承载力,并降低刚度退化幅度。

Link beam is an important component of the linked column steel frame structure. The traditional link beam often has the first failure of the weld between the stiffening rib and the web under the reciprocating load, thereby reducing the plastic rotation ability. In order to improve link beam rotation capacity and make it enter the plastic energy consumption as early as possible, the link beam with slotted hole web can be used to replace the traditional link beam. The hysteretic behavior of the linked column steel frame structure with slotted hole webs was analyzed by ABAQUS finite element analysis software. The analysis results showed that the increase of the thickness t w of the link beam’s web could increase the stiffness, bearing capacity and energy dissipation capacity of the structure. The smaller the ratio of length to width β of column between holes to web, the better the structural performance. Considering the stress concentration and the initial defects of the steel, it was recommended that β should be 1~1.2. The increase of the length L of link beam with the slotted hole web could improve the energy dissipation capacity of the structure. However, when L was too long, the plasticity development was insufficient, and the material performance could not be fully exerted. It was preferable to take the main structural span of 0.16~0.22 times. Lifting the frame steel grade could significantly increase the structural load capacity and reduce the stiffness degradation.