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

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.

Integrating Electromechanical Systems in Commercial Vehicles for Improved Handling, Stability, and Comfort

“…First introduced by Ahmadian [61], groundhook control differs from skyhook in that the damper is now connected to the unsprung mass rather than the sprung mass, as shown in Through the same reasoning used for skyhook, groundhook control can be expressed as: (2.4) In this configuration, the focus shifts from the sprung mass to unsprung mass. Whereas skyhook performed well in controlling the sprung mass, groundhook is effective in controlling the unsprung mass excitations, as shown in transmissibility plots in Figure 2.14.…”

Design of a hybrid proportional electromagnetic dynamic vibration absorber for control of idling engine vibration

“…Dynamic vibration absorbers (DVAs) have been widely used for effectively attenuating vibration in many engineering application such as rotating machines and structures. 1 , 2 The inherent performance limitations of the fixed parameters of passive DVAs are also well-known. Considerable efforts have been made during the past many decades to identify optimal parameters of DVAs in attempt to overcome the primary limitation associated with the narrow vibration absorption frequency range of the DVA.…”

Optimization of damped dynamic vibration absorber to control chatter in metal cutting process

“…They also showed that active control of tool damping in each of the principal modal directions led to quite effective chatter suppression. Koo and Ahmadian (2002) investigated the dynamic characteristics of semi-active ground hook tuned vibration absorbers and the results were compared with those of passive tuned vibration absorbers. Mei (2005) designed an active feedback wave controller to absorb chatter vibration energy in a broad frequency band to improve machining performance of a boring process by considering a real distributed cutting system model.…”