Dynamic Vibration Absorber

About: Dynamic Vibration Absorber is a research topic. Over the lifetime, 4764 publications have been published within this topic receiving 49429 citations.

Adaptive-passive vibration control system

Abstract: A passive-adaptive vibration control system is provided wherein various elements of the system may be adapted on-line in response to sensed vibrations. A spring/weight vibration absorber (160, 165) is attached to a vibrating body, such as the drum (115) of a laundry machine (100), to absorb energy generated by the drum, to minimize the transmission of vibrations to a structure, such as the body of the machine (100) in mechanical communication with the drum. The mass of the weight (160) of the vibration absorber may be adjusted, on-line, to compensate for sensed vibrations. A vibration sensor (170) is connected to the vibrating body so as to sense the level of vibration above a desired level and to send a signal representative of that vibration to an electronic controller (180). The electronic controller (180) is designed to instruct an actuator arrangement (182, 184) to adapt the mass of the weight to compensate for the sensed vibration. For example, the weight (160) may be a chamber, the mass of which may be adjusted by adding or releasing a fluid to or from the chamber via the actuator arrangement (182,184) under the control of the controller (180).

Vibration control of an electrorheological fluid-based suspension system with an energy regenerative mechanism:

Abstract: This work presents vibration control of a vehicle suspension system using a controllable electrorheological (ER) shock absorber activated by an energy generator without external power sources. The ER shock absorber has a rack and pinion mechanism which converts a linear motion of the piston to a rotary motion. This rotary motion is amplified by gears and subsequently activates a generator to produce electrical energy. The generated voltage is experimentally evaluated with respect to excitation magnitude and frequency of the ER shock absorber. After evaluating the damping force using the regenerated voltage, a quarter-car ER suspension model is established. A skyhook controller is then formulated and experimentally implemented to attenuate vibration using the regenerated energy. It has been demonstrated via experiment that suspension vibration under bumpy and sinusoidal road conditions is significantly controlled by activating the ER shock absorber operated by the proposed regenerative energy mecha...

Pendulum as Vibration Absorber for Flexible Structures: Experiments and Theory

Abstract: The dynamic response ofa beam-tip mass-pendulum system subjected to a sinusoidal excitation is investigated. A simple pendulum mounted to a tip mass of a beam is used as a vibration absorber. The nonlinear equations of motion are developed to investigate the autoparametric interaction between the first two modes of the system. The nonlinear terms appear due to the curvature of the beam and the coupling effect between the beam and pendulum. Complete energy transfer between modes is shown to occur when the beam frequency is twice the pendulum frequency. Experimental results are compared with a theoretical solution obtained using numerical integration. The experimental results are in qualitative agreement with the theory.

Vibration Control to Avoid Stick-Slip Motion:

Abstract: Friction-induced self-sustained oscillations result in a very robust limit cycle that characterizes stick-slip motion. This type of motion should be avoided under any circumstances because it creates noise, wear, and damage. In this paper we show, by simple models, how stick-slip motion can be avoided. Effective methods are: (i) appropriate increase of internal damping that compensates the negative damping induced by a friction characteristic, which decreases with increasing sliding speed; (ii) external excitation that breaks up the limit cycle (however, this often leads to chaotic motion); (iii) passive vibration control by fluctuating normal forces. The last mentioned mechanism is new and will be investigated in detail. The stick-slip oscillator is extended by an additional degree of freedom, which couples the slipping motion to the normal force. The dynamic behavior of the system has been worked out by analytical investigations and numerical integration. Scanning a broad range of values, parameters of ...