MTMD减震结构体系的频域分析

将主结构简化为串联多自由度模型,通过对主结构稳态响应的频域传递函数的模值来分析MTMD控制效果。主结构稳态响应的频域传递函数分别采用以下三种方法求取:1)推导结构系统振动方程,将其从时域转化为频域,推导频域传递函数;2)将MTMD系统对主结构的反力与地震荷载共同作为主结构的荷载输入,根据MTMD的反力为各阶模态耦合对结构进行控制的方法求取频域传递函数;3)根据MTMD的反力为各阶模态非耦合对结构进行控制的方法求取频域传递函数。利用以上方法分析MTMD系统对主结构的单模态和多模态进行控制的控制效果。根据非耦合控制作用的频域传递函数提出惯性质量参与量。给出一算例,并且给出时程分析的结果加以比较验证。

ANALYSIS OF MULTISTORY STRUCTURES WITH MTMD IN FREQUENCY DOMAIN

In this paper, single-mode and multi-mode control of the seismic response of multistory structures with MTMD is investigated. The multistory structures are predigested as MDOF systems in series. Response is obtained using the absolute value of transfer function of harmonic response of structure in the frequency domain, which is deduced by means of three different methods. In the first method, the differential equation of structure system with MTMD is given and transformed from time domain into frequency domain. The transfer function in frequency domain is obtained. In the second method, the reaction of MTMD to structure and the earthquake load are taken as input of structure. The transfer function is deduced considering structural mode coupling. In the third method, the transfer function is obtained considering structural mode uncoupling. Inertia mass participation coefficient is presented which elucidates the action mechanism between MTMD and structure. They are illustrated, and compared with the dynamic time history analysis result. For control of multistory structures with MTMD, multi-mode control is superior to single-mode control. For analysis precision, considering modes coupling is superior to doing mode uncoupling. For shearing model, the result with uncoupling meets the engineering demand.