空间张弦结构抗震性能研究

为了了解空间张弦结构的动力特性及其抗震性能,首先对该结构和无下部索杆体系的单层网壳进行自振特性分析,然后通过时程分析讨论空间张弦结构在地震作用下的动力响应,并研究了撑杆数量、垂跨比、上弦梁刚度、预应力及拉索截面面积等参数对其动力性能的影响.分析结果表明下部索杆体系能增大空间张弦结构的刚度,空间张弦结构的低阶振型以竖向振动为主.撑杆数量、垂跨比及上弦梁截面的增加有利于增大结构刚度及提高结构抵抗整体变形的能力,但预应力和下弦拉索面积对空间张弦结构抗震性能的影响较小.

Study on the Seismic Performance of Space Beam String Structures

The dynamic characteristic of space beam string structure was investigated in this paper. The modal analysis was firstly carried out with this structure and the corresponding upper single-layer shell without the lower cable-strut system. Then the time history analysis were performed to study the dynamic behavior of space beam string structures under earthquake action, including the effect of numbers of struts, sag-span ratios, stiffness of upper beams, prestress and area of cables. The results show that the lower cable-strut system does increase the stiffness of space beam string structures, and most vibration modes of the structure are vertical modes. The increase of numbers of struts, sag-span ratios and sections of upper beams are conducive to increase of structural stiffness and resisting global deformation. But the effect of prestress and area of lower cables on the seismic performance of space beam string structure is slightly.