拉链柱支撑钢框架结构静力推覆试验及数值模拟

为研究拉链柱支撑钢框架结构在水平荷载作用下的承载能力、抗侧刚度、破坏模式以及构件的传力模式等，对一个3层单跨1:2.6缩尺比例的拉链柱支撑钢框架进行了静力推覆试验及数值模拟。结果表明：在对应8度多遇及设防烈度地震作用工况的水平侧移下，结构基本处于弹性工作状态，构件未出现明显失稳现象。在对应8度罕遇地震作用工况的水平侧移下，由于支撑失稳导致结构抗侧刚度明显降低，但结构的承载力并无明显下降，随着加载的进一步进行，因支撑失稳产生的竖向不平衡力主要由拉链柱承担，且该不平衡力由此逐层向上传递，导致顶层支撑的轴压力逐渐增加；当反向卸载时，拉链柱构件承担部分压力，但并未失稳。总体上，结构各构件的受力状态及传力过程与设计目标基本一致，结构在静力推覆试验中表现出良好的受力性能。

Pushover test and numerical analysis of zipper frames

In order to investigate the seismic performance of zipper frames, including the structural bearing capacity, lateral stiffness, failure mode and force transmission of structural members, a pushover test and numerical analysis were carried out on a 3-story and 1:2.6 scaled single-span zipper frame model. The test and numerical analysis results show that, under the lateral displacements corresponding to the frequent and design level earthquake events with intensity 8, the frame model remains in the elastic stage and no buckling is observed on the structural members. Under the lateral displacements corresponding to the rare earthquake event with intensity 8, the structural lateral stiffness is decreased obviously after buckling of the brace members. However, the structural bearing capacity doesn’t decrease significantly. With the increase of lateral displacements, the unbalanced vertical force due to buckling of the brace members, is transferred upwards mainly through elongating the zipper struts. Then, the compressive force in the top story braces is increased. When the zipper frame model is unloaded, the zipper struts are subjected to compressive forces，but no buckling is found on these members. In general, the force state and force-transfer path of the structural members are basically in accordance with the design intention and the zipper frames show good seismic performance in the pushover test.