低容量液流阻尼器之性能測試與應用

Abstract

本研究旨在探討與合作廠商所研製之低容量液流阻尼器的力學特性與工程應用—包括設備基座之減振，以及房屋結構﹙含木造與鋼結構﹚之防震應用。為了解液流阻尼器之力學行為，本文根據流體動力學理論，考慮非牛頓流體，建立了液流阻尼器之流體動力分析模式。經由參數分析，探討活塞面積、活塞厚度及孔隙大小對於液流阻尼器力學行為之影響，並發現阻尼係數與勁度之頻率相依特性，此乃習用之Kelvin model所無法模擬者。元件測試結果顯示，合作廠商研製之液流阻尼器有飽滿而穩定之遲滯消能特性，其性能較日本原廠提供之阻尼器更為優異。設備基座減振測試結果顯示，低容量液流阻尼器展現極佳之減振效果，三分之一倍頻分析證明其有效之控制範圍極廣，整體而言以30~100Hz的頻寬內減振效果最為顯著。以振動台完成之一系列結構耐震性能測試結果，顯示低容量液流阻尼器無論應用於木造結構或鋼結構上，均能發揮減振效果，具有成為結構抗震阻尼器之應用潛力。

The objective of this study is to explore the developement mechanical characteristics of the low-capacity fluid dampers through our cooperation with company with possible industrial applications in control of machine-induced vibration, and earthquake resistance of building structure (on both wood and steel model structures) . To get more insight of the mechanics of viscous fluid dampers, a fluid dynamic model has been developed based on theories in fluid dynamics with consideration of non-Newtonian fluid. The effects of piston area, piston thickness and gap of the annular orifice on the mechanical behavior of the fluid dampers are assessed via the parametric study. Both the damping coefficient and stiffness of the fluid damper are found to be frequency- dependent, which could not be reflected by using the Kelvin’s model. Results of the component tests indicate that the fluid dampers developed by cooperation with company exhibit rich and stable energy-dissipative characteristics superior to those of the prototype by the Japan manufacturer. Effectiveness of the low-capacity fluid dampers in machine-induced vibration control have been observed via the simulation tests. The dampers are proved to be effective in a wide range of spectrum as revealed from the one-third octave spectrum analysis, and generally speaking, the control effect is most prominent within the bandwidth of 30~100 Hz. A series of seismic performance tests of the fluid dampers for structural response control by the shaking table has been conducted. Experimental results for both the wood and steel model structures show that the fluid dampers are effective in seismic vibration control. The potential of using fluid dampers for earthquake protection of building structures has been confirmed.