斜拉网壳结构的构件分析和非线性动力计算

MEMBER ANALYSIS AND NONLINEAR DYNAMIC RESPONSES OF CABLE-STAYED RETICULATED SHELL STRUCTURES

斜拉网壳结构是空间网壳结构与柔性拉索族系的有机结合。文中导出了空间杆单元几何非线性刚度矩阵，阐明了斜拉索的非线性特性和塔柱计算，给出了结构非线性动力响应计算策略并做数值分析。计算表明，该类结构频谱密集，且自振频率明显高于对应的网壳结构；反应谱法与时程分析法的计算结果差别较大，因此对大跨度（斜拉）网壳结构须用后者验算。

The Cable-Stayed Reticulated Shell Structure (CSRS) is a kind of so-called hybrid structural system, composed of cables, towers and Reticulated Shell Structures (RSS). This paper focuses on the basic members such as the 3-D bar element, cable element and tower-column element, as well as the nonlinear dynamic responses of the CSRS. A novel Total Lagrangian formulation of a 3-D bar element for large displacement and infinitesimal rotation analysis is developed. The nonlinear properties of a cable element, and a novel simplified linear stiffness matrix of a tower-col- umn element which cable elements link to are investigated. The computational strategies for the nonlinear seismic responses of the structures are also developed. Some numerical examples of CSRS and RSS are given. It is clear that the frequency spectra of both CSRS and RSS are very dense, and that the vertical responses are much greater than the horizontal responses. It should be pointed out that for the same element, the ratios of the internal force obtained by using response spectra theory and time history response analysis respectively are guite different.