半柔性悬挂结构体系的减振机理及其减振效果分析

Analysis of the mechanism and efficiency of vibration-absorption for semi-flexible suspension systems

提出一种新型高层建筑半柔性悬挂减振结构体系。给出体系的结构方案,简化计算模型及多自由度体系运动方程;在时域内输入El Centro波和Taft波来阐明体系的动力特性;基于随机地震动激励采用复模态解耦与虚拟激励法相结合,推导这种体系的随机动力响应表达式;编制相应程序以主体核筒顶点位移和柔性层层间位移为控制目标,对影响结构动力响应的阻尼器刚度和阻尼系数及柔性悬挂楼段设置位置进行优化分析。结果表明:这种体系能够较好地降低地震响应,有着较大的柔性层层间位移和较小的悬挂楼段层间位移;存在最优的阻尼器阻尼系数,能够明显减小主体核筒动力响应;阻尼器的刚度有助于控制柔性层的层间位移;悬挂楼段设置在结构上部对顶点位移的减振效果更好。

An innovative tall building system, named semi-flexible suspension systems, is proposed. The configuration, simplified model and the formulation of the multi-degree of freedom equations of motion for the structure are provided. The E1 Centro and Taft earthquake time histories are also introduced to identify the dynamic characteristics of the system in the time domain. Random seismic response is determined by combining the generalized modal analysis approach with a pseudo-excitation method. Based on the derived formula, a computer code is developed, and parametric studies, on parameters such as the locations of suspension systems, the damping coefficient and stiffness of the dampers, are performed to control the top floor displacement of the primary core-tube and the inter-story drift of the flexible layer and to identify the beneficial parameters of the damper devices. Results show that this structure can effectively reduce seismic responses of the core-tube, with larger inter-storey drift in the flexible layers and smaller inter-story drift in the suspension systems, that there is an optimal damping coefficient leading to a minimum response of the core-tube, that reasonable damper stiffness is helpful for control of the inter-storey drift of the flexible layer, and that suspension systems at the top segment may effectively reduce the top displacement.