斜拉立体桁架极限承载力的双重非线性分析

斜拉立体桁架是一种有发展前途的大跨度杂交结构体系。针对两塔三跨和一塔两跨两种结构形式,基于UL列式,采用混合有限元模型,对该结构体系进行了几何非线性屈曲分析以及几何、材料双重非线性屈曲分析,得出斜拉立体桁架的极限承载力。计算结果表明,只有同时考虑结构的几何和材料非线性的屈曲分析方法,才能准确地评估出结构的极限承载力。同时研究了不同塔高、桁架高度、索距以及跨度对结构极限承载力的影响,从中得出了一些结论可供设计人员参考。

GEOMETRIC AND MATERIAL NONLINEARITY ANALYSIS FOR DETERMINING ULTIMATE LOAD CAPACITY OF CABLE-STAYED SPACE TRUSS

Cable-stayed space truss is a long span hybrid structural system with developing prospect.Based on the equation of updated Lagrangian formulation,through mixed finite element model,buckling analyses of geometric nonlinearity and geometric & material nonlinearity of two types of structure including two towers with three spans and one tower with two spans are carried out.The ultimate load-carrying capacity is achieved.It is shown that the ultimate load-carrying capacity can be evaluated accurately only simultaneously considering both geometric and material nonlinearity.In addition,the effects of different parameters,including heights of tower and truss,distances between cables as well as spans,on the ultimate load capacity of cable-stayed space truss are discussed.Some conclusions can be served as reference for engineers in the design.