大跨度空间索桁张力结构的模型试验研究

针对一种新型的大跨度空间结构体系———环形平面葵花型空间索桁张力结构,在理论研究基础上,设计了外径5m、内部椭圆开口3.8m×3.2m,由12组空间索桁基本分析单元构成的结构模型并进行了试验研究。测试了多种预应力水平、多种荷载工况、多级加载等条件下结构的静力性能及其多阶模态频率与振型,并与理论计算结果进行了比较。试验结果表明,在一定的预应力形成结构刚度后,体系的自平衡内力分布可通过理论找力计算获得;在对称荷载作用下,结构具有良好的承载能力与稳定性,其静力反应基本呈线性;结构抵抗不均匀荷载的能力较强,构件内力趋于整体均匀重分布;其低阶模态以竖向振动为主,结构具有良好的侧向水平刚度。

An experimental study on large-span spatial cable-truss tensile structure model

The sunflower-shaped spatial cable-truss tensile structure with annular plane is a new type of large-span spatial structural system.A structural model with outer diameter of 5 meters,inner oval opening of 3.8 m×3.2 m and 12 basic units of spatial cable-truss was constructed and tested on the basis of theoretical considerations.The static behavior,free-vibration frequency and mode of the structure with different prestress levels under the condition of multiple loading cases and multi-step loading were studied,and the calculated results of finite element analysis were verified by the test data.The investigation shows that after the necessary structural rigidity is provided with the feasible prestress introduced,distribution of self-equilibrium forces of the system can be performed by numerical analysis.The structure has good load-carrying capacity and stability,and its mechanical behavior is linear elastic under symmetrical loading.The structure presents strong resistance to asymmetrical loads,and the structural member forces tend to be redistributed uniformly.The lower modes are characterized by vertical vibration,and the structure has excellent lateral rigidity.