超大跨度凯威特型巨型网格结构选型及参数分析

Structural selection and parametric analysis of super-large span Kiewitt type mega-latticed structures

通过对不同体系超大跨度空间结构研究成果的回顾,探讨了其发展趋势。对比分析了800 m跨度、相同荷载作用下具有相同几何参数的双层网壳、局部三层网壳、肋环型巨型网格和凯威特型巨型网格结构体系的多项静力性能指标。结果表明:在相同跨度和荷载作用下凯威特型巨型网格结构体系受力性能最优。针对此结构体系的空间复杂性,利用CAD三维成型分析获得其拓扑关系,明确了跨度、矢高、桁架高度等7个几何形体控制参数。基于结构几何成型的程序化实现方法,利用APDL参数化语言首次得到其自动生成程序,并编程完成了结构分析计算。最后对凯威特型巨型网格结构体系展开了包括环(径)向分割份数、矢跨比、桁架高跨比在内的7个参数共计153个模型、1 000余算例的大规模参数分析。总结了结构力学性能随上述参数的变化规律,归纳了各参数的合理取值范围,为该巨型结构的理论研究与工程设计提供参考。

The research results on super-large span structures based on various types of structural system are reviewed and the development tendency of the structure is proved. Static behaviors of double-layer reticulated shell,local triplelayered reticulated shell,ribbed type mega-latticed and Kiewitt type mega-latticed structures with the same geometrical parameters（ 800 m span） and load were compared. The results show that Kiewitt type mega-latticed structures have best mechanical performance with the same span and loads. Then,for the space complexity of this structure,the structural configuration was analyzed through CAD 3D modeling and seven key structural form parameters,such as span,rise and height of truss,were determined. Furthermore innovative structural-programming method based on geometrical configuration was conducted,and the mechanical performance of Kiewitt type mega-latticed structures was studied based on the program which can create the structure automatically by APDL parametric language. A great number of parametric evaluations including 153 models and more than one thousand examples were studied for seven parameters,including circumferential / radial divisions,rise-span ratio and height-span ratio of truss. The mechanical property with the variation of the parameters and the reasonable value range of every parameter were summarized. The study is the basis of further research and guidance for actual engineering design.