基于单柱子结构模型的型钢混凝土异形柱框架抗震性能混合试验研究

Seismic hybrid simulation of steel reinforced concrete frame with specially-shaped columns based on single column substructure model

为研究实腹式型钢混凝土异形柱框架结构的抗震性能,以一榀三层两跨异形柱中框架为原型进行整体结构抗震混合试验。基于试验装置构建的OpenSees-OpenFresco-MTS混合试验系统,分别选取底层十字形截面中柱和T形截面边柱作为试验单元,利用四联杆设备对其进行加载,其余部分作为计算单元基于OpenSees软件进行时程分析。通过观察不同试件的受力过程及破坏特征,分别获得试验单元和整体框架的动力反应,对比分析了其滞回特性、累积耗能及刚度退化等,并对震损柱进行拟静力试验。研究结果表明:型钢混凝土十字形中柱和T形边柱试验单元及整体框架的滞回曲线饱满,耗能能力强;震损柱的前期刚度下降迅速,后期刚度下降平缓,破坏时刚度约为初始平均刚度的30%;基于不同试验单元下整体框架的耗能结果初始状态和最终状态趋于一致,体现了混合试验方法的正确性及经济性。

In order to investigate the dynamic seismic behaviors of solid-web steel reinforced concrete frame with specially-shaped columns, seismic hybrid test of a two-bay and three-story middle frame served as prototype integral structure was conducted. The hybrid test system named OpenSees-OpenFresco-MTS was setup based on the existing equipment of laboratory. The cross-shaped section interior column and T-shaped exterior column on bottom story served as experimental elements were loaded with four-bar linkage device respectively and the rest of the structures served as numerical elements were carried out time history analysis with OpenSees. Then the dynamic response of different experimental elements and the whole frame were obtained by observing the loading process, failure characteristics of specimens, and further analysed the hysteretic curves, energy dissipation and stiffness degradation. Quasi-static test was carried out to explore the residual performance of the damaged specimens. The results show that different experimental elements and the whole frame have full hysteretic loops and good energy dissipation capability. The early stiffness of seismic damaged column decreases rapidly, the late stiffness decreases slowly, and the failure stiffness is 30% of the initial average stiffness. The initial and final energy dissipation responses of whole frame based on different experimental elements show the same results, which verifies the correctness and economy of hybrid test.