子结构刚度对巨型框架减振结构体系的动态特性影响

建立随机风载激励下巨型框架减振结构体系的动力方程，基于随机振动复模态理论，推导位移响应谱及均方响应的计算表达式，并对一巨型钢框架减振结构体系在Davenport风速谱下的响应特性进行了计算，讨论了子结构刚度变化时结构体系的减振特性。结果袁明：子结构的刚度变化对巨型框架减振结构体系的减振效果是非常敏感的，当子结构的刚度发生变化时，可以形成3个不同的控制机理区域，在第一、二区域中能使结构的第一振型得到有效的控制，获得好的减振效果。

On Improving the Self-Absorption of Shock of Mega-Frame Building

Mega substructure, an isolated substructure used in mega frame building, has attracted more and more attention of designers for shock absorption in mega frame building. The obvious advantage is the elimination of the separate TMD (Tuned Mass Damper) or MTMD (Multiple Tuned Mass Dampers). However, how to estimate the influence of mega substructural stiffness on the dynamic property of this shock absorption structure system remains as yet unsolved. A satisfactory way of estimating such influence is essential to improving the self absorption of shock of mega frame building. This paper aims to provide a way for satisfactorily estimating such influence. Section 2 gives in some detail the derivation of eq. (9) as the response of shock absorption system of mega frame building under pulsating wind loading. The derivation employs well known principles of engineering vibration. However, two points are perhaps worth mentioning: (1) the use of frequency domain method in random vibration theory allows the clear identification of spectrum distribution against each frequency of the mega frame building as a whole. (2) The replacement of generally used SDOF (Single Degree of Freedom) model for each mega substructure by MDOF (Multiple Degrees of Freedom) model for each mega substructure allows the estimate of capability of the mega substructure to absorb shocks corresponding to its second and higher natural frequencies. Section 3 takes a certain mega frame building in Tokyo, Japan, as an example to illustrate that significant improvement of its self absorption of shock is possible through better design of its three identical mega structures. The results, calculated by our method for the original design and for our suggested design and then compared in Figs.4 and 5, show preliminarily that our suggested design can indeed improve significantly the self absorption of shock of mega structure building.