黏滞阻尼器型伸臂桁架的最优布置形式研究

The study of optimal arrangement form of outrigger trusses with viscous dampers

随着超高层建筑结构体系的高度不断突破刷新,越来越多的超高层建筑采用了中间核心筒与外围框架相结合的结构形式,通过设置伸臂桁架来协调核心筒与框架间的受力和变形,减小核心筒底部弯矩和结构顶部位移,但会带来结构刚度、内力突变等不利影响。本文以兰州金茂大厦为背景,采用ANSYS有限元软件建模和目标函数法优化比选,研究了设置黏滞阻尼器的5种不同布置形式伸臂桁架的抗震性能。结果表明:竖向斜撑型是满足抗震要求的黏滞阻尼器型伸臂桁架的最优布置形式,但同时单斜撑型的阻尼器利用率最高,竖向斜撑型的阻尼器利用率最低。

With the height of super high-rise buildings being refreshed, more and more tall buildings introduce the system of frame-core tube structure which applies outrigger trusses to harmonize the force and deformation between core tube and frame. Outriggers can reduce the top displacement and bottom moment of core tube. However, they can bring adverse effects such as abrupt change of structural stiffness and internal force. Based on Lanzhou Jin Mao Tower, this paper studies the seismic performance of five outriggers with viscous dampers throughout ANSYS model- ing and objective function method. The results show that the type of vertical inclined brace is the optimal arrange- ment forms among five types. Meanwhile, the highest utilization rate of dampers occurs in the type of single diago- nal brace and the lowest occurs in the type of vertical inclined brace.