大跨度混凝土悬挑空腹桁架结构静动力特性研究

以某市规划展览馆工程为背景,对混凝土大跨度悬挑空腹桁架结构的静、动力特性进行详细分析研究。空腹桁架支承于框架柱上,桁架高度8.4 m、悬挑跨度22 m,荷载较大。设计了不同腹杆布置形式的三种结构方案,用有限元软件ANSYS和MIDAS,建立了包含框架柱、桁架、楼盖梁板的整体结构的空间力学模型,其中,桁架的杆件、框架梁和柱用空间梁单元模拟,楼板用三维壳单元模拟。研究表明,三种结构的挠度、杆件内力、结构自振频率及振型等静动力指标均可满足工程要求,其中,具有交叉布置斜腹杆的桁架结构的力学指标较为优异。

The Study of Static and Dynamic Characteristics for Long-span Concrete Cantilever Vierendeel Truss Structure

Based on the project of Zunyi Planning Exhibition Hall,this paper provides detailed analysis and research on static and dynamic characteristics of the long-span concrete cantilever vierendeel truss structure.The vierendeel truss is constructed on the frame column.The height of the truss is 8.4 meters and its overhang span is 22 meters,so the load is quite huge.We designed three different structure programs on the arrangement of web members.using finite element software Ansys and Midas,we established air-mechanics model which includes the whole structure of frame column,truss and beams.The bar of truss and frame beam is simulated by spatial beam element.The floor is simulated by 3D shell element.The research shows that the deflection,bar internal forces,structure natural frequency and modal of these three structure programs can satisfy the demand of this project.Among them,the mechanical properties of the truss structure which has cross-layout inclined web members are relatively good.