斜拉立体桁架的几何非线性分析

斜拉立体桁架是一种有发展前途的杂交结构体系，不需增加结构高度和构件断面，就能比较经济地跨越很大的跨度。本文基于UL列式，结合斜拉立体桁架的特点，采用了空间梁单元、空间杆单元、拉索单元相结合的混合有限元模型，分别对1塔柱2跨和2塔柱3跨两种不同形式的斜拉立体桁架进行了几何非线性静力分析，研究了由于拉索的垂度、大位移以及二者都考虑引起的非线性效应，并和线性分析作了对比，最后得出了一些结论供设计人员在设计中参考。

Geometric nonlinear analysis of cable-strayed space truss

Cable - strayed space truss is a promising hybrid system, which can have the capacity to go beyond longer span without increasing the height of structure and section of members. Based on the equation of updated Lagrangian formulation, mixed finite elements of spatial beam, rod and cable are used to analyze the whole structure according to the characters of the structure. Geometrical nonlinear analyses about two towers with three spans and one tower with two spans are performed in this paper. In addition, the influences of the sagging effect of cable, large displacement as well as both of them are taken into account and discussed respectively. Compared with the linear result, some conclusions can be obtained for reference in the design.