Dynamic Analysis of Semi-Active Tuned Vibration Absorbers Using Closed-Form Equivalent Models

Abstract

Abstract The main purpose of this study is to investigate dynamic characteristics of semi-active Tuned Vibration Absorbers (TVAs) using an adjustable damper, such as a Magneto-Rheological (MR) damper. Based on on-off and continuous control polices, closed-form groundhook equivalent models are developed for analytical studies of semi-active TVA models. In addition, the transmissibilities of groundhook equivalent models are compared with passive TVAs. The results indicate that semi-active 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 reducing the amplitude of resonant peaks at the expense of increasing vibrations at the tuned frequency. A parametric study of the groundhook TVAs shows that the effectiveness of semi-active TVAs increases with larger on-state damping, larger mass ratio, and smaller off-state damping.