地震基频对TMD最优动力特性影响的评价

EVALUATION ON EFFECT OF SEISMIC CHARACTERISTIC FREQUENCY ON OPTIMUM DYNAMIC CHARACTERISTICS OF TMD

基于虚拟激励法和Clough_Penzien地震谱 ,利用导出的设置TMD结构位移和加速度传递函数 ,建立了结构的位移动力放大系数 (DDMF)和加速度动力放大系数 (ADMF)计算公式。于是TMD优化准则为 :Min .Min .Max .DDMF和Min .Min .Max ,ADMF。通过最优搜寻得TMD最优调谐频率比和阻尼以及相应的控制有效性指标。考虑结构受控频率与地震基频的不同比值 ,研究地震基频对TMD最优参数及其有效性的影响。研究表明 ,在利用TMD控制结构的地震反应时 。

Based on both the pseudo-excitation approach and Clough-Penzien spectrum and using the developed displacement and acceleration transfer functions for the structure with TMD, the displacement and acceleration dynamic magnification factors(i.e. DDMF and ADMF) are, respectively, defined and their explicit expressions are formulated. The criteron for optimum searching is the minimization of the minimum values of displacement dynamic magnification factor(i.e. Min. Min, Max. DDMF) as well as that of the minimum values of acceleration dynamic magnification factor(i.e. Min. Min. Max, ADMF). After optimum searching, the TMD optimum parameters and corresponding indexes representing the control effectiveness are obtained. Through selecting the different values of the ratio of structural frequency of the controlled mode to seismic characteristic frequency, the research is carried out on the influence of seismic characteristic frequency on TMD optimum parameters and its effectiveness. It is shown that in reducing the seismic responses of structure by use of TMD, the controlled frequency of structure should be lower than the seismic characteristic frequency.