结构半主动变阻尼控制的研究

作为经典范例之一,半主动变阻尼系统得到了广泛的应用,然而近来的研究显示仍需要对其控制性能重新认识。本文以谐波作用下支座激励的理论为出发点,讨论了粘性变阻尼控制系统可能成立的基本条件和适用范围。算例以一个设置在基础层的半主动变阻尼器控制系统为例,采用离复位控制策略进行了数值模拟,并得出了两个重要结论:(1)变阻尼控制系统只有在结构动力反应远离共振的情况下,才有可能同时取得位移峰值和加速度峰值的减小;(2)结构动力反应与控制效果的改善依赖地面运动特性,在一般情况下相比被动阻尼控制并不能明显提高控制效果,甚至有所不及。

Study on Semiactive Structural Control Using Variable Dampers

It's well known that the semiactive control system is very attractive due to a large control force capacity,a small power demand and its inherent stability.As a classical example the semiactive variable damper is widely used,however,the latest research results show that its performance still need to be further studied.In this paper based on the theory of a SDOF vibration-isolation system under harmonic excitation,the basic conditions and limits of the applicability of viscous variable dampers are discussed.As a numerical example a sixstory base-isolated frame is considered.According to the qualitative analysis and numerical simulation,two important conclusions are drawn :(1) Only far from the resonance may reductions in both the displacement and acceleration responses be possible for structures with viscous variable dampers;(2) The effectiveness of viscous variable dampers on reducing the response of structures depends on the characteristics of the ground motion that excites structures.In contrast to that of passive dampers,the effect of variable dampers is not better,even its effect is inferior.