液压蓄能竖向隔震系统力学特性研究

Study on the mechanical characteristics of vertical seismic isolation system employing hydraulic apparatus

关键词:  竖向隔震  液压系统  谐波平衡法  数值分析  位移传递率

Key words:  vertical isolation  hydraulic system  harmonic balance method  numerical analysis  displacement transmissibility

摘要:

为解决现有隔震装置普遍侧重水平向而竖向控制薄弱的问题,本文提出一种新型液压蓄能竖向隔震体系,以有效抑制结构的竖向地震响应。首先,分析了系统的刚度特性,通过静力试验验证了隔震系统的力学性能和阻尼耗能能力。其次,建立了隔震系统动力学模型,采用谐波平衡法求解系统的幅频响应和位移传递率,分析了振动幅值、阻尼比和蓄能器体积压缩系数对位移传递率的影响。最后,建立了液压蓄能竖向隔震混凝土框架结构和未隔震框架结构的有限元模型,对上述模型进行了地震动动力时程分析,对比分析了两种框架的地震响应结果。研究结果表明:液压蓄能竖向隔震混凝土框架结构的竖向加速度响应与地面输入相比平均降低了59%,竖向隔震效果明显。

Abstract:

To address the limitation that existing seismic isolation devices mainly focus on horizontal directions while providing insufficient vertical control, a novel hydraulic accumulator-based vertical seismic isolation system was proposed to mitigate the vertical seismic response of the structures. The system′s stiffness characteristics were analyzed, followed by experimental validation to assess its mechanical performance and energy dissipation capability. A dynamic model of the isolation system was then established, and the harmonic balance method was employed to determine the system′s amplitude-frequency response and displacement transmissibility. The effects of vibration amplitude, damping ratio, and accumulator volumetric compression coefficient on the displacement transmissibility were analyzed. Finally, finite element models for both the vertical seismic isolation structure and a conventional frame were established and subjected to seismic time history analysis, and the seismic response results of the two frameworks were compared. The analysis results show that the vertical acceleration response of VSI-HCA structures is reduced by an average of 59% compared to the ground input, indicating a significant vertical isolation effect.