The objective of this study is to mitigate, or even completely eliminate, the limit cycle oscillations in mechanical systems using a passive nonlinear absorber, termed the nonlinear tuned vibration absorber (NLTVA). An unconventional aspect of the NLTVA is that the mathematical form of its restoring force is not imposed a priori, as it is the case for most existing nonlinear absorbers. The NLTV...

A new tuning method for active vibration absorber design is presented in this paper. A robust, adaptive control scheme based on a variable structure with an adaptive discontinuity surface is designed and simulated. Robust synthesis of an adaptive discontinuity surface based on an augmented state-space is discussed. The proposed tuning scheme has three superior features compared with the existin...

Vibro-elastography is a new medical imaging method that identifies the mechanical properties of tissue by measuring tissue motion in response to a multi-frequency external vibration source. Previous research on vibro-elastography used ultrasound to measure the tissue motion and system identification techniques to identify the tissue properties. This paper describes a hand-held probe with a comb...

Formulas for the optimal design of single-degree-of-freedom (SDOF) tuned-mass dampers (or dynamic vibration absorbers) for SDOF structures under random and harmonic excitations have been available for many years. Whenever an absorber body is attached to a primary system, there is potential for utilization of motion in more than one degree of freedom of the body relative to the primary system. I...

In this paper, different semi-active control strategies for non-linear quarter car model equipped with controllable magneto-rheological (MR) shock absorbers and fuzzy logic controller are compared. Polynomial model is selected to characterize the experimental results of MR shock absorber. A combination of Forward Fuzzy Logic Controller (FFLC) and Inverse Fuzzy Logic Controller (IFLC) is designe...

The possibility of suppressing self-excited vibrations of mechanical systems using parametric excitation is discussed. We consider a two-mass system of which the main mass is excited by a ow-induced, self excited force. A single mass which acts as a dynamic absorber is attached to the main mass and, by varying the stiiness between the main mass and the absorber mass, represents a parametric exc...