某张拉整体塔结构动力特性及地震反应分析

Structural dynamic characteristics and seismic responses for a tensegrity tower

以在天津塘沽区拟建的某张拉整体塔雕塑为背景,分析了预应力大小对张拉整体塔结构自振特性的影响规律。研究发现,张拉整体塔各阶自振频率随预应力的增大而增大,但10阶后的频率基本与预应力水平无关;在多遇地震和罕遇地震作用下,结构杆件内力变化和节点位移均满足规范要求,罕遇地震作用下各杆件动静比明显大于多遇地震,杆件动静比随初始预应力的增大而减小;罕遇地震下,结构在多维地震作用下的响应一般大于单维,XY向和XYZ向地震作用响应基本一致。

A tensegrity tower in Tanggu district of Tianjin to be used as a city sculpture is taken as the research background.Its natural vibration properties and seismic responses were analyzed. Research results show that the structural frequencies of the tensegrity tower increase with the increase of the prestress level. However,the frequencies after 10 steps barely have relationship with the change of prestress level. In the case of frequently occurred earthquake and rare occurrence earthquake,the members internal forces and joint displacement meet the requirements of the specification. Dynamic to static ratio of all member under rare occurrence earthquake are much larger than those under frequently occurred earthquake and decrease with the increase of prestress level. In the case of rare occurrence earthquake,structure response under multidimensional excitations is generally greater than that under single dimension. Besides,structure responses under XY direction and XYZ direction are nearly the same.