Suppression of Vibrations

Acoustical Society of America Journal, 2004

Title: Vibration damping system and a method of damping vibrations. Authors:Bhattacharya, Bishakh. Publication: Acoustical Society of America Journal, Volume 116, Issue 2, pp. 628-628 (2004). Publication Date: 08/2004. Origin: STI. ...

Earthquake Resistant Engineering Structures VII, 2009

This paper presents new types of mechanical devices, developed by SITON in cooperation with other units in Romania, by means of which to control, limit and damp shocks, vibrations and seismic movements in buildings, equipment and pipe networks. The new devices, called "SERB-devices", can overtake static loads over which dynamic loads may overlap and be damped. The devices allow "cuttingoff" the dynamic action incoming from the environment to the protected systems (building, equipment, pipe network, etc) and the overtaking of shocks and vibrations generated by the systems to protect the environment. The devices may have high relative displacements, with or without elastic reaction force, thus allowing the performance of a good isolation of the components against the dynamic action, also overtaking the displacements due to thermal expansions or support yielding. The devices are made of materials that practically are not affected by the aging phenomenon and relative large temperature variations and may be guaranteed throughout the service-life of each unit, without maintenance or repair. The devices are small in size if compared with the existing ones for similar performances. The radiation resistance capacity is very good and therefore allows their use in nuclear-power plants.

Conference on Decision and Control, 2010

An active vibration control system using an inertial actuator for suppression of multiple unknown and/or time-varying vibrations will be presented. The objective is to minimize the residual force by applying an appropriate control effort through the inertial actuator. The system does not use any additional transducer for getting in real time information upon the disturbances. A direct feedback adaptive regulation

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2010

This paper presents the design of a multimode vibrations suppression compensator for numerical controlled mechatronic systems. The compensation strategy requires knowledge about the modal behavior of the non-compensated system and a reference model. The non-compensated system's modes are defined by second order discrete transfer functions. The reference model has the same modal structure and parameters as the non-compensated system, except for the damping ratios that are 1. The compensator is the result of the division of the reference model by the non-compensated model. Two examples of such compensators are shown, one for singlemode and one for multimode systems. The method in this paper is focused on discrete time systems suitable for implementation on DSPs and numerical computers.

A method of vibration reduction using dampers with controllable dissipative characteristics is presented in the paper. Mathematical formulation of the problem leads to the evaluation, at every instant of time, an optimal value of damper's force based on a criterion being taken into consideration. It is proved in the paper that the optimization problem with unilateral constrains being formulated herein possesses an analytical solution in the case of one-degree of freedom dynamical system. The method can be used for vibration reduction of civil structures and machinery in the case of both dynamic and kinematic excitations. The simulation of a system with controllable damper using MATLAB/Simulink software is analysed.

2017

This damping device comprises: two symmetrical jacks (10, 10'), extending respectively between each Support member (8, 6) and the housing (4), each jack (10,10) defining two chambers (24, 24', 26, 26") filled with a hydraulic fluid (16, 16), two hydraulic lines (28, 28) establishing fluid communi cation between, on the one hand, the first chambers (24, 24") of the jacks and, on the other hand, the Second chambers (26, 26") of the jacks, two branch lines (30, 30") opening into two accumulators (32,32) containing a compressed gas, and means (34, 36, 40, 42) capable of providing a controlled flow rate of the fluid outside the said cham bers (24, 24', 26, 26) and means (38, 44) capable of providing a controlled flow rate of the fluid to the accumulators.

Journal of Materials Processing Technology, 2007

A vibration isolation and vibration suppression device is presented. The device consists of an electromagnetic actuator and a magneto rheological fluid (MRF) rotary shear damper. In the device, the MRF damper supports a vibrating body. Since the body is connected to the base with large rigidity using the MR damper, vibrations are small when an exciting force acts on the body directly. When base vibrations occur, the electromagnetic actuator under the disturbance force cancellation control isolates vibrations, where the shear force of the damper is controlled to be small. This device can control both vibrations due to exciting force acting on the body and base vibrations without using a heavy vibration table. To validate the system, experimental tests have been performed, and it is clarified that this device works well. Especially, the transmissibility in low frequency region can be suppressed within one.

Journal of Structural Control, 1996

The aim of the present paper is to investigate two strategies for the active control of plate vibrations, using distributed sensors and actuators (PVDF patches) working on a wide frequency band. The two strategies correspond to the two ends of a spectrum ranging from very robust/less efficient schemes (analog static output feedback) to less robust/very efficient schemes (here ‘frequency shaped LQG’).Both have been experimentally tested and have given successful attenuations; the efficiency of both approaches is demonstrated on sensor signals involved in the control loop as well as on radiated pressure measurements, which constitute an independent index of performance.It is shown that ‘frequency shaped LQG’ is a viable approach to feedback control of lightly damped structures, and that its robustness can be enhanced through a careful design.LQG is a model‐based method, and hence requires the modeling of the active structure. Two approaches are investigated in this paper: a finite ele...

some small deviation in design and installation anti vibration mount/the right method for vibration control/