索系-空间杂交结构的动力特性和参数分析

研究由网壳、索系和塔柱构成的索系-空间杂交结构协同工作体系的动力特性，并进行参数分析．采用空间杆单元和空间梁单元分别构建网壳杆件和塔柱构件的力学模型；采用空间索单元并引入等效弹性模量对拉索进行力学建模．分析和比较网格形式、索系布局、结构支承、矢跨比、杆件截面及其尺寸等有关参数对结构动力性能的影响．结果表明，索系-空间杂交结构体系自振模态可分为塔柱在网壳结构切向的振动、塔柱在网壳径向的振动、整体结构协同振动和网壳结构自身振动等4个组群；结构各组群振动的自振频率相对集中，其出现顺序依赖于该类结构的具体构形及网壳、索系和塔柱的刚度．

Dynamic Characteristics and Parameter Analysis of Long-Span Reticulated Structure with Cables

The long-span reticulated structure with cables(LRSC)is a kind of cooperating working system,which consists of flexible cables,reticulated structure(RS) and tower columns.The cooperating effect or spatial coupling vibration makes structural dynamic stiffness changing nonlinearly.The spatial bar element and spatial beam element was adopted to describe the mechanical models of the members of reticulated structure and tower columns respectively.And,the spatial cable element with introducing equivalent elastic modulus was given to establish cable mechanical model.The effect of such parameters as grid configuration,cable arrangement,structural bearings,structural span-to-depth ratio and member sectional dimension on structural dynamic characteristics were analyzed and compared.The study shows that the vibration modes of LRSC can be divided into four groups.The vibration frequencies in the same group are very close while the frequencies in different groups are different from each other obviously.It is clear that the sequence of the appearance of each mode group heavily depends on the comparative stiffness of the tower column system,RS and cables.