A qualitative analysis of groundhook tuned vibration absorbers for controlling structural vibrations

Abstract

Abstract

The primary purpose of this study is to investigate the dynamic characteristics of semi-active groundhook tuned vibration absorbers (TVAs), using closed-form equivalent models of such systems. Closed-form, equivalent models of groundhook TVAs are developed and compared analytically with those for passive TVAs. Additionally, closed-form solutions of groundhook equivalent TVA models are obtained and are used for a parametric study to evaluate the dynamic characteristics of such systems as various parameters change. The numerical results are compared with passive TVAs which have been studied extensively in the past. The results indicate tat groundhook TVAs, with off-state damping levels within a critical value, are capable of lowering the magnitude of resonant peaks without increasing vibration. In contrast, increasing damping in passive TVAs results in a reduction in the amplitude of resonant peaks, at the expense of increased vibrations at the tuned frequency. The results further indicate that increasing the mass ratio between the TVA and the structure increases the effectiveness of groundhook TVAs, in a manner much similar to passive TVAs. However, increasing off-state damping decreases the effectiveness of groundhook TVAs.