分层装配式支撑钢结构工业化建筑体系抗震性能试验研究

Experimental research on seismic performance of floor-by-floor assembled steel braced structures for prefabricated buildings

对2层4跨足尺结构进行了拟静力加载试验,考察了分层装配式支撑钢结构在水平地震作用下的抗侧力机制、破坏模式与滞回特性,以及刚度和承载力的变化规律。试验结果表明,支撑是主要抗侧力构件,结构弹性阶段的抗侧刚度几乎完全由支撑提供,研制的新型支撑具有良好的延性工作性能。结构体系在往复荷载下失效演进过程表现为支撑受压失稳、支撑受拉屈服、柱脚截面部分屈服、节点处梁翼缘循环拉压变形、柱脚端板连接焊缝开裂和柱脚全截面屈服形成塑性铰。改进后的梁贯通式节点可以保证框架在塑性大变形阶段分担相当比例的水平地震力,因而可作为该结构的第2道防线。鉴于结构体系耗能能力一般,抗震设计时可以考虑一定的地震作用放大系数。

A quasi-static experiment was carried out on a full scale two-story by four-span structural system.Lateral force resisting mechanism,failure modes and hysteretic properties of the improved floor-by-floor assembled steel braced structure were investigated,as well as the evolution of the structural stiffness and strength under horizontal earthquake.Test results show that the braces are the primary members to resist the lateral load,the elastic lateral stiffness is exclusively provided by the braces.The developed new braces demonstrate good ductile behavior.The structural damage evolution under cyclic loading includes compression buckling and tension yielding of braces,partial yielding of column base,cyclic deformation of beam flange,weld cracking and plastic hinge formation at the column bases.The beam-column frame can participate in resisting horizontal seismic force under the conditions of large story drift due to the improved beam through connections.Thus,it can be viewed as the second defense of the structural system.It is recommended that a certain magnification factor for seismic action should be considered in the seismic design to compensate the low energy dissipation capacity.