高强钢组合K形偏心支撑框架抗震性能对比分析

Comparative analysis on seismic performance of high strength steel composite K-shaped eccentrically braced frames

为研究不同强度组合的高强钢组合K形偏心支撑框架结构的抗震性能,设计了一组不同强度(Q345、Q460、Q690钢材)组合的5层K形偏心支撑框架结构算例Q345-5、Q460-5和算例Q690-5,选取10条地震动记录对其进行动力时程分析,得到各算例在不同水准地震作用下的耗能梁段转角和层间位移角。研究表明:8度罕遇地震作用下,高强钢组合K形偏心支撑框架的层间位移角比传统K形偏心支撑钢框架大,各算例耗能梁段全部进入塑性变形阶段;塑性层间位移角到达规范限值时,算例Q460-5框架梁开始进入塑性变形阶段,算例Q690-5框架柱、框架梁和支撑均处于弹性变形阶段,还可以承受更大的地震作用;达到定义的极限状态时,与传统偏心支撑钢框架相比,算例Q460-5能够承受的地震作用和耗能梁段转角更小;算例Q690-5承受的地震作用和耗能梁段转角更大。

To study the seismic performance of high-strength steel composite K-shaped eccentrically braced frames(KHSS-EBFs)with steels of varying strengths,three 5-story K-HSS-EBFs with different combinations of steel strength were designed with Q345-5,Q460-5,and Q690-5 steels.The dynamic time-history analysis was performed using 10 seismic ground motions.The rotation angles of links and inter-story drift ratio of the samples at different levels of earthquake were obtained.The results show that under 8-degree rare earthquakes,the inter-story drift ratio of the KHSS-EBFs is larger than that of the conventional K-shaped EBF,and the links of all samples enter the plastic deformation stage.When the plastic inter-story drift ratio reaches the specification limit,the frame beams of Q460-5 begin to enter the plastic deformation stage.In contrast,the frame columns,frame beams and braces of Q690-5 are found to be in the elastic deformation stage for such earthquakes and can withstand greater seismic action.In the limit state,compared with the conventional K-shaped EBF,the seismic impact that the structure could withstand and the link rotation angle obtained with Q460-5 are smaller,while in the case of the Q690-5 samples,they are larger.