高强钢组合K形偏心支撑钢框架震后修复试验研究

Experimental study on seismic retrofit of high strength steel composite K-type eccentrically braced frames

高强钢组合K形偏心支撑钢框架通过低屈服点耗能梁段的弹塑性变形耗散能量,结构破坏主要集中于此,可通过更换耗能梁段完成结构修复。为研究替换构件法修复这种结构的可行性和修复后结构的抗震性能,先对1榀单层单跨1/2缩尺的高强钢组合K形偏心支撑钢框架进行循环加载试验;将已加载破坏的试件进行更换耗能梁段修复,再对修复后的试件进行循环加载试验。试件破坏模式和主要抗震性能指标的分析结果表明:采用替换耗能梁段法修复这种结构是可行的,且修复工作量小,有利于尽快恢复正常;修复后的极限承载力与原试件相当,但延性系数略有降低;相同层间位移角下二者耗散能量差别不大,但修复后的耗能梁段转动能力不及原试件。

In the high strength steel composite K-type eccentrically braced frames,seismic energy were dissipated by inelastic deformation of low yield point steel link,and the main failures were concentrated on links also. This structure can be retrofitted by replacing the damaged link. In order to study the feasibility and effect of this kind of seismic retrofit,the one-bay one-story 1 /2 scaled plane specimen was tested under cyclic load,then the damaged specimen was repaired by replacing the link. Finally,the retrofitted specimen was tested under cyclic loading as the previous one. The failure modes and the main indexes of seismic behavior of two specimens were analyzed. The results show that the method of link replaced is feasible for this structure seismic retrofitting,and it is easy to complete because of less work. The ultimate capacity of retrofitted specimen was almost equal to the original one＇s,but the ductility is slightly lower. The difference of energy dissipating at same story drift between two specimens is very minor,but the link rotation capacity of retrofitted specimen is less than the original one.