斜撑对方钢管柱-桁架梁节点抗震性能影响试验

Experiment on the effect of the diagonal brace on the seismic behavior of square hollow column-truss beam connections

为实现施工现场绿色、高效率、高精度的模块化装配式钢结构建筑的建造,分别提出基于柱座式的带斜撑和不带斜撑的装配式方钢管柱-桁架梁节点。共设计4个十字形足尺试件,并对其进行滞回加载试验。分别考察梁破坏和斜撑破坏模态下试件的抗震性能,探究两种破坏模态产生的原因。评估斜撑对节点极限承载力、延性、刚度以及能量耗散能力等抗震性能的影响,分析两种破坏模态下节点的传力机制,并结合破坏模态和受力特性分别给出带斜撑和不带斜撑节点的设计建议。结果表明:不设置斜撑的试件表现出良好的塑性变形和能量耗散能力等抗震性能;斜撑的设置不仅有效地将塑性铰由桁架梁转移到斜撑端部,而且大幅度地提高节点的承载力和刚度,但在斜撑破坏前桁架梁塑性变形能力受限。整个加载过程中,4个试件的柱座与桁架梁之间的连接未出现破坏,且柱子与柱座之间的法兰板未出现明显的滑移现象,该柱座式连接可靠。

In order to achieve the construction of environmentally-friendly,efficient,and highly precise modular assembled steel structure buildings at construction sites,this study introduces two types of assembled square hollow column-truss beam connections:one with diagonal braces and one without diagonal braces.Four full-scale cross-shaped specimens were meticulously designed for the purpose of conducting cyclic loading tests.The seismic behavior of these specimens was thoroughly investigated under both beam failure and diagonal brace failure modes,and the underlying causes for the occurrence of these failure modes were elucidated.Furthermore,the impact of diagonal braces on crucial aspects such as ultimate bearing capacity,ductility,stiffness,and energy dissipation capacity was comprehensively evaluated.Finally,an analysis of the mechanisms underlying these two failure modes was conducted,and the design suggestions of joints with and without diagonal braces were respectively given in combination with the failure modes and mechanical performances.Remarkably,the experimental results indicate that the specimens without diagonal braces exhibited commendable seismic behaviors in terms of plastic deformation and energy dissipation capacity.The incorporation of diagonal braces effectively transferred plastic deformation from the truss beam to the end of the diagonal brace,resulting in a significant enhancement of the connections' bearing capacity and stiffness.However,it should be noted that the plastic deformation capacity of the truss beam was constrained prior to diagonal brace failure.During the whole loading process,the connection between the column seat and the truss beam of the four specimens did not show any damage phenomenon,and there was no obvious slip phenomenon of the flange plate between the column and the column seat,which indicates that the column seat type connection was reliable.