可更换双槽形Q235耗能梁段钢框筒子结构抗震性能试验研究

为改善传统钢框筒结构延性差和震后修复困难的问题，提出了带双槽形腹板螺栓连接可更换剪切型耗能梁段的钢框筒结构(SFTS-RSLs)。为研究SFTS RSLs的抗震性能和耗能梁段的可更换能力，对2种耗能梁段长度(400 mm和280 mm)的2/3缩尺单跨双半层SFTS-RSLs子结构进行两阶段拟静力试验；基于耗能梁段腹板的往复拉压试验标定混合强化模型参数；基于两子结构加载阶段Ⅱ的试验结果验证了子结构试件有限元模型的有效性，并对耗能梁段转动能力受耗能梁段长度和加固板的影响进行分析。结果表明：长度分别为400 mm和280 mm的双槽形Q235耗能梁段的可更换最大层间位移角分别为0.32%、0.27%；超强系数均大于Popov等建议的1.5，塑性变形能力均满足美国规范ANSI/AISC 341-16的要求；替换耗能梁段可以使子结构性能接近初始水平；设短双槽形耗能梁段的子结构延性、累积耗能相比设长耗能梁段的子结构的明显降低；子结构破坏模式为双槽形耗能梁段加劲肋倒角处的焊缝裂缝扩展延伸引起的腹板撕裂；建议取双槽形耗能梁段长度与柱距之比为0.14~0.23，并应考虑连接处布置耗能梁段加固板。

Experimental study on seismic behavior of steel framed tube substructures with a replaceable double-channel Q235 link

Steel framed-tube structures with double-channel web-bolted connected replaceable shear links (SFTS-RSLs) were proposed to resolve the problem of poor ductility and difficult post-earthquake repair of traditional steel framed-tube structures. In order to study the seismic behavior of SFTS-RSLs and replaceability of double-channel links, two 2/3 scale one-bay and double-half-story substructures of SFTS-RSLs with two link lengths (400 mm and 280 mm) were subjected to two-stage pseudo-static tests. The parameters of the nonlinear isotropic/kinematic hardening model were calibrated based on reciprocating tension and compression tests of the link web. The FE models of the substructure specimens were validated based on the stage Ⅱ test results of the specimens, and the influence of the double-channel link length and the reinforcement plate of the link on the rotation capacity of the links were analyzed. The results show that the replaceable maximum story drift angles of double-channel Q235 shear links with lengths of 400 mm and 280 mm are 0.32% and 0.27%, respectively. Their overstrength factors are greater than the value of 1.5 recommended by Popov et al, and their plastic deformation capacity meets the requirements of American standard ANSI/AISC 341-16. Replacing the links can make the performance of the substructure close to the initial level. The ductility coefficient and cumulative energy dissipation of the substructure with the short double-channel link are significantly lower than those with the long double-channel link. The failure modes of the substructures are web tearing failure caused by the expansion of weld crack at the chamfer of the stiffeners of the link. The double-channel link length is recommended to take 0.14-0.23 times the column distance, and the reinforcement plate of the link should be considered at the joints in design.