基于磁流变阻尼器的半刚性悬挂结构体系避震机理及地震响应分析

EARTHQUAKE AVOIDANCE MECHANISM AND SEISMIC RESPONSE ANALYSIS FOR SEMI-RIGID SUSPENDED STRUCTURE SYSTEMS USING MR DAMPERS

提出一种新型建筑结构体系——半刚性悬挂结构体系,并在该体系中合理设置磁流变阻尼器。阐述了该体系的基本组成和计算模型,推导了其运动方程和动力响应函数。通过时域内输入El Centro波、Taft波以及天津波,验证了该体系具有良好的减振避震性能。根据随机振动理论,推导了体系的随机振动响应表达式;以主体核筒顶点位移和半刚性层的层间位移为目标函数,对体系中影响结构动力响应的磁流变阻尼器输入电压进行参数分析。计算结果表明:该体系能够有效减小地震响应,半刚性层层间位移较大,主体结构顶点位移和悬挂楼层层间位移较小;对于该文给定的算例,输入电压存在最优值,最优值约为16V;当磁流变阻尼器输入电压为最优值时,主体结构动力响应和半刚性层层间位移均可得到很好的控制,结构达到最佳避震效果。

A novel building structure system, namely semi-rigid suspended structures, is put forward in thispaper. Magnetorheological fluid dampers （MRFD） are properly designed in systems. The basic composition andcalculation model for the structure system are described. And the motion equations and dynamic responsefunction are also derived. The E1 Centro, Taft and Tianjin earthquake waves are used to calculate the dynamiccharacteristics in the time domain, of which the vibration reduction and earthquake avoidance performance areproved satisfactory. Based on the random vibration theory, random seismic responses of the structure are derived.Taking the top floor displacement of the primary core-tube structure and the inter-story displacement of thesemi-rigid story as an objective function, the structural parameter optimization analysis for the input voltage ofMRFD are performed with MATLAB. The results show that the seismic responses of this novel structure can be reduced effectively, with relatively larger inter-storey displacements in the semi-rigid stories and relativelysmaller inter-story displacements in the top floor displacement of a primary structure and in the suspended stories.For the calculation example in this paper, the optimal value of the input voltage of MRFD is 16V. When the inputvoltage of MRFD is optimal value, the seismic responses of the primary structure and the inter-story displacementof a semi-rigid story can be well controlled, and the earthquake avoidance performance of the structure is improveobviously.