地震激励下高层建筑主次结构间桁架节点的力学性能分析

Mechanical Performance Analysis of Truss Joints Between Primary and Secondary Structures of High-rise Buildings under Earthquake Excitation

高层建筑主次结构间桁架节点形状复杂,抗震性能分析困难。采用Sap2000软件建立高层建筑主次结构间桁架的有限元模型,充分考虑高层建筑主次结构间桁架形状的不规则特性和桁架结构中形状相对比较规则的特性,给出桁架节点区的抗剪机理和抗侧刚度计算方法,并在模拟分析中,考察地震激励作用下,高层建筑主次结构之间桁架的力学性能,发现主框架梁承担着所有的次柱轴力,主梁在跨度内出现显著的剪力值突变,主框架梁在结构中起到重要的稳定性作用。层间位移角曲线沿楼层高度呈现周期性分布,说明结构刚度分布不均匀。本研究为高层建筑主次结构桁架的抗震设计提供参考。

The shape of truss joints between primary and secondary structures of highrise buildings is complex,making their seismic performance analysis difficult.In this paper,a finite element model of a truss between the primary and secondary structure of a highrise building was established with SAP2000 software.Irregular characteristics of the truss shape between the primary and secondary structures of the highrise building and the regular shape of the truss structure were fully considered.The shear mechanism and method of calculation of the lateral stiffness of the truss joints are presented.In the simulation analysis,the mechanical properties of the trusses under seismic excitation were investigated.It was found that the main frame beam bore all of the axial forces of secondary column,and the main beam had a significant shear value mutation in the span.The main frame beam played an important role in the stability of the structure.The periodic distribution of the interstory drift ratio curve along the floor height indicated that the stiffness distribution of the structure was uneven.The study provides a reference for seismic design of primary and secondary structural trusses of highrise buildings.