索穹顶结构动力特性及多维多点抗震性能研究

Study on dynamic characteristics and behavior of cable dome subjected to multi-dimensional and multi-point seismic excitations

为了弥补索穹顶这种新型大跨空间结构在动力方面研究的不足,通过对120m跨度的肋环形索穹顶结构进行模态分析,得到了不同的参数对索穹顶结构的自振频率影响曲线;通过对其进行时程分析,发现了地震动的行波效应对结构的节点位移和杆件内力的影响规律,以及考虑多维地震与仅考虑地震单向输入之间的差别,为大跨空间结构的抗震设计提供了重要参考.研究表明,多点输入对于行波方向的位移影响显著,同时,对单元内力产生不利影响,因此,大跨度空间结构抗震分析中考虑行波效应与多维地震输入是必要的.

A 120 m span cable dome was analyzed and the affection curve of cable dome frequency vs different parameters was obtained. Based on the time history analysis of the cable dome, the traveling-wave effect on the structure's nodal displacements and post's inner forces were found, and the difference between multi-dimensional seismic excitations and one-dimensional seismic excitation was obtained, which provided the important reference for anti-seismic design of large span space structures. The research indicates that the effect of the multi-dimensional seismic excitations to the displacement of the traveling-wave direction is obvious and that the effect to the element force is also negative, so it is necessary to consider the seismic traveling wave effect the and multi-dimensional seismic excitations in the anti-seismic analysis of large span space structures.