基于平稳过滤有色噪声地震动模型的MTMD性能评价

Performance evaluation of multiple tuned mass dampers based on the stationary filtered non-white noise model for seismic ground motions

研究了由许多刚度和阻尼保持为常量且频率呈线性分布的TMDs形成的MTMD的地震特性。基于虚拟激励法和平稳过滤有色噪声地震动模型,建立了结构-MTMD系统的传递函数,进而导出了设置MTMD时结构的动力放大系数(DMF)明确表达式。于是MTMD的优化准则可定义为Min.Min.Max.DMF。通过最优搜寻可得MTMD的最优频率间隔、平均阻尼比、调谐频率比和相应的无量纲控制有效性指标。目前的论文通过考虑结构受控频率与地震加速度卓越频率比的不同取值和不同场地类型,研究地震卓越频率和场地类型对MTMD最优参数及有效性的影响。同时与基于Kanai-Tajimi平稳过滤白噪声地震动模型和不考虑地震加速度卓越频率(ωg=∝)两种情况的结果进行了比较。

Seismic behavior of the multiple tuned mass dampers (MTMD), consisting of many tuned mass dampers (TMDs),which keep the stiffness and damping constant and have a uniform distribution of natural frequencies,is studied in the present paper.Based on both the pseudo\|excitation approach and stationary filtered non\|white noise model for the seismic ground motions,the transfer function for the structure with MTMD is formulated.The explicit expression for the dynamic magnification factor of the structure with MTMD, denoted by DMF, is derived.The criterion for the optimum searching is then the minimization of the minimum values of the maximum dynamic magnification factors (i.e.Min.Min.Max.DMF).Through the optimum searching,one may obtain the optimum frequency spacing,average damping ratio, tuning frequency ratio, and corresponding index representing the control effectiveness of MTMD.With resorting to selecting the different values in the ratio of the structural frequency in the mode to be mitigated to the dominant ground frequencies and taking the soil classification into account, the research is carried out on the influences of the dominant ground frequencies and soil classification on the MTMD optimum parameters and effectiveness.Additionally, the results on the performance of MTMD are compared with those based on the Kanai\|Tajimi model (i.e.the stationary filtered white noise model) for the seismic ground motions and without considering the dominant ground frequency (i.e.ωg=∝).