设置组合工字钢梁的自复位框架抗震性能试验研究

基于“可恢复功能抗震结构”的设计理念，设计并制作了一种设置组合工字钢梁的自复位框架，采用消能杆作为耗能元件，进行了由不同消能杆组成的4个自复位框架的低周往复荷载试验，在分析其受力机理的基础上，对比分析了结构的受力发展过程、耗能能力和卸载后的自复位能力。结果表明：各自复位框架的试验宏观现象基本相同，其荷载-位移滞回曲线均呈“双旗帜”形；锚固板开口后，框架的抗弯刚度由预应力钢绞线和消能杆提供；层间侧移角加载至4%时，骨架曲线仍无下降趋势，结构具有良好的承载能力和变形能力；自复位框架的塑性变形都集中于消能杆，更换消能杆后，结构的抗震性能得以迅速恢复，实现了震后易于修复的设计目标；通过对残余层间侧移角和等效黏滞阻尼系数的分析表明，结构具有良好的自复位能力和耗能能力，且框架的抗震性能主要由自复位参数确定。

Experimental study on seismic behavior of self-centering steel frame with composite I-beam

Based on the design concept of the earthquake resilient structure, a new type of self-centering steel frame with composite I-beam was designed and manufactured. The energy dissipation bar which was similar with buckling restrained brace was used as energy dissipation element. Four frame specimens composed of different energy dissipation bars were designed to conduct low cyclic loading test. Based on analysis of stress mechanism, the load transfer mechanism, energy dissipation capability and self-centering capability of specimens were analyzed and compared. Test results show that the test phenomena of specimens are basically the same. The load-displacement hysteretic curves of specimens are double flag-shaped. After opening of anchor plate, the flexural stiffness of frame is provided by post-tensioned steel strand and energy dissipation bar. While the inter-story drift angle of specimen reaches 4%, the skeleton curve doesn’t act descending trend, which shows the frame has excellent bearing capacity and deformation capacity. The plastic deformation of specimens is concentrated on energy dissipation bars, and the seismic performance of the structure can be restored after replacement of energy dissipation bars. The design intention of easy repairing after earthquake is realized. The analysis of residual inter-story drift angle and equivalent viscous damping coefficient shows that the structure has good self-centering capability and energy dissipation capability which is mainly determined by self-centering parameter.