scholarly journals Vibration Characteristics of Beam Structure Attached with Vibration Absorbers at its Vibrational Node and Antinode by Finite Element Analysis

2020 ◽  
Vol 1 (1) ◽  
pp. 7-16
Author(s):  
W. S. Ong ◽  
Muhd Hafeez Zainulabidin
Keyword(s):  
Vibration Amplitude ◽  
Vibration Characteristics ◽  
Optimum Number ◽  
Vibration Absorbers ◽  
Beam Structure ◽  
Dynamic Vibration Absorber ◽  
Element Analysis ◽  
Dynamic Vibration ◽  
Amplitude Increase ◽  
Modes Of Vibration

In this study, the vibration characteristics of fixed ends beam are analysed after attached with dynamic vibration absorbers at vibrational node and antinode by simulation using ANSYS APDL. This study aim to obtain the best location and optimum number of DVAs placed on the fixed ends beam in order to reduce vibration of beam. The dynamic vibration absorber were attached to the fixed ends beam vibrational node and antinode for a total of three modes of vibration. The 0.84 m long beam is modelled by ANSYS and divided into 21 elements where each element is 0.04 m. A harmonic force, Fo of 28.84 N is exerted at node 3 of beam element. Modal analysis and harmonic analysis are carried out in this study to obtain the natural frequency and frequency response of the beam respectively. The vibration characteristics of fixed ends beam without DVA and beam attached with DVAs were compared. The simulation results show reduction of vibration amplitude of the beam especially when the DVA were attached at the vibrational antinode. The DVA amplitude increase when amplitude of beam decreases. From this study, it is proved that DVAs absorb vibration of the beam structure. The best position to attach DVAs is the vibrational antinode based on the modes of vibration. The increment of DVAs number will not affect the percentage reduction of vibration amplitude as long as the DVAs are placed at optimum location.  

Research on Frequency-Tuned Dynamic Vibration Absorber

2011 ◽  
Vol 66-68 ◽  
pp. 1762-1768
Author(s):  
Shi Liang Jiang ◽  
Tie Jun Yang ◽  
Jing Tao Du ◽  
Yin Yin Hu
Keyword(s):  
Vibration Absorber ◽  
Beam Structure ◽  
Dynamic Vibration Absorber ◽  
Bending Vibration ◽  
Element Analysis ◽  
Simply Supported Beam ◽  
Vibration Absorption ◽  
Simply Supported ◽  
Dynamic Vibration ◽  
Resonance Frequencies

A frequency-tuned dynamic vibration absorber by tuning stiffness to reduce vibration at some troubled resonance frequencies of a simply supported beam structure is designed in this paper. Both theoretical and simulation analysis of vibration absorption are conducted. On the basis of analyzing bending vibration of the simply supported beam structure, inherent characteristics and frequency response characteristics of the simply supported beam system before and after being fixed dynamic vibration absorber are obtained by using the energy method with Rayleigh-Ritz procedure of flexible structure. Simulation model of the whole system, which is established by code written, is compared with the model established by finite element analysis software. Results are presented to show the efficiency of the vibration absorber, and then the effect of damping of the dynamic vibration absorber on vibration absorption is studied.

Dynamic Vibration Absorber Optimal Design With Emphasis on Complete Machine Dynamics Modelling

2008 ◽  
Author(s):  
Bohdan M. Diveyev ◽  
Zinovij A. Stotsko
Keyword(s):  
Optimal Design ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Rotating Machines ◽  
Dynamic Vibration Absorber ◽  
New Methods ◽  
Dynamic Vibration ◽  
Methods Development ◽  
Dynamic Vibration Absorbers ◽  
Dynamics Modelling

The main aim of this paper is improved dynamic vibration absorbers design with taking into account complex rotating machines dynamic The is considered for the complex vibroexitated constructions. Methods of decomposition and the numerical schemes synthesis are considered on the basis of new methods of modal methods. Development of of complicated machines and buildings in view of their interaction with system of dynamic vibration absorbers is under discussion.

scholarly journals Fluid-Induced Vibration Elimination of a Rotor/Seal System with the Dynamic Vibration Absorber

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Qi Xu ◽  
Junkai Niu ◽  
Hongliang Yao ◽  
Lichao Zhao ◽  
Bangchun Wen
Keyword(s):  
Natural Frequency ◽  
Nonlinear Differential Equations ◽  
Damping Ratio ◽  
Force Model ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Major Purpose ◽  
Rotating Speed ◽  
Dynamic Vibration ◽  
Nonlinear Responses

The dynamic vibration absorbers have been applied to attenuate the rotor unbalance and torsional vibrations. The major purpose of this paper is to research the elimination of the fluid-induced vibration in the rotor/seal system using the absorber. The simplified rotor model with the absorber is established, and the Muszynska fluid force model is employed for the nonlinear seal force. The numerical method is used for the solutions of the nonlinear differential equations. The nonlinear responses of the rotor/seal system without and with the absorber are obtained, and then the rotating speed ranges by which the fluid-induced instability can be eliminated completely and partially are presented, respectively. The absorber parameters ranges by which the instability vibration can be eliminated completely and partially are obtained. The results show that the natural frequency vibration due to the fluid-induced instability in the rotor/seal system can be eliminated efficiently using the absorber. The appropriate natural frequency and damping ratio of the absorber can extend the complete elimination region of the instability vibration and postpone the occurrence of the instability vibration.

Dynamic Vibration Absorber Design to Suppress Boring Chatter: Absorber Parameters Identification Based on Modal Correlation

2013 ◽  
Vol 753-755 ◽  
pp. 1816-1820 ◽  
Author(s):  
Zhen Kun Hu ◽  
Ming Wang ◽  
Tao Zan
Keyword(s):  
Damping Ratio ◽  
Correlation Method ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Element Analysis ◽  
Simple Method ◽  
Dynamic Vibration ◽  
The Finite Element Analysis ◽  
Chatter Control ◽  
Modal Method

The dynamic vibration absorber (DVA) is generally used to suppress the machining vibration in boring processes. The DVA consists of an additional massspringdamper sub-system, and needs accurately tuning of its natural frequency and damping ratio to match the main structure for vibration control. For obtaining the optimal performance of the DVA, the parameters of the DVA used in a boring bar is identified using modal correlation method, which combines the finite element analysis method with test modal method to validate the FEMs results. The analysis results show that the modal correlation method is an effective and simple method to accurately identify the dynamic parameters of DVA and guarantee the optimal design of the DVA for boring chatter control.

Numerical and Experimental Studies of Pendulum Dynamic Vibration Absorber for Structural Vibration

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Seon Il Ha ◽  
Gil Ho Yoon
Keyword(s):  
Experimental Studies ◽  
Point Of View ◽  
Structural Vibration ◽  
Vibration Absorber ◽  
Square Root ◽  
Vibration Absorbers ◽  
Structural Vibrations ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Resonance Frequencies

Abstract This research presents a pendulum dynamic vibration absorber (PDVA) consisting of a spring and a mass in order to attenuate structural vibrations at two frequencies of hosting structure. It is a convention to attach several dynamic absorbers to hosting structure for the sake of the attenuations of structural vibrations at multiple frequencies with enlarged bandwidth and often it increases the total mass and the installation cost. Therefore, the reduction of the number of vibration absorbers for multiple excitation frequencies is an important issue from an engineering point of view. To resolve these difficulties, this study proposes to adopt the vibration absorber framework of the spring-mass vibration as well as the pendulum vibration simultaneously with the present PDVA system. It is composed of a spring and a mass but being allowed to swing circumferentially, the structural vibrations at the two resonance frequencies, i.e., the square root of stiffness over mass and the square root of a length over gravidity, can be simultaneously attenuated. As the length of the spring of the present PDVA is varied, the effective ranges for the pendulum dynamic vibration absorber become widen. To prove the concept of the present PDVA, this research conducts several numerical simulations and experiments.

Analysis of Parallel Damped Dynamic Vibration Absorbers

1969 ◽  
Vol 91 (1) ◽  
pp. 282-287 ◽  
Author(s):  
A. V. Srinivasan
Keyword(s):  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Main Mass ◽  
Dynamic Vibration ◽  
Frequency Comparison ◽  
Dynamic Vibration Absorbers ◽  
Tuning Frequency ◽  
Comparison Of The Results ◽  
Operational Range

The analysis of parallel damped dynamic vibration absorbers is presented. The system considered is essentially a modification of the conventional damped vibration absorber and consists of adding, in parallel, a subsidiary undamped absorber mass in addition to the damped absorber mass. The analysis clearly shows that it is possible to obtain an undamped antiresonance in a dynamic absorber system which exhibits a well-damped resonance. While the bandwidth of frequencies between the damped peaks is not significantly increased, the amplitudes of the main mass are considerably smaller within the operational range of the absorber. The damped absorber mass and the main mass attain null simultaneously so that the vibratory force is transmitted directly to the undamped absorber. Numerical results are presented for the special case when the absorber masses have the same magnitude. Two cases of tuning have been considered: (a) when the absorber masses are tuned to the frequency of the main mass, and (b) when the absorber masses are tuned to the so-called favorable tuning frequency. Comparison of the results with those of the conventional absorber indicates that the parallel damped dynamic vibration absorber has definite advantages over the conventional damped vibration absorber.

Suppressing Wind-Induced Oscillations of Prismatic Structures by Dynamic Vibration Absorbers

2017 ◽  
Vol 17 (06) ◽  
pp. 1750056 ◽  
Author(s):  
W. B. Liu ◽  
H. L. Dai ◽  
L. Wang
Keyword(s):  
Equations Of Motion ◽  
Oscillation Amplitude ◽  
Coupled System ◽  
Vibration Absorbers ◽  
Governing Equations ◽  
Dynamic Coupling ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Linear Damping ◽  
Dynamic Vibration Absorbers

The suppression of oscillations of an elastically mounted prism under galloping by a dynamic vibration absorber (DVA) with linear damping and stiffness is investigated. A model considering the dynamic coupling of the prism and the DVA is constructed, with the aerodynamic loads acting on the system represented by a quasi-steady approximation. Based on the coupled nonlinear governing equations of motion, a linear analysis is first conducted to explore the coupled frequency and damping, and the onset speed of galloping in the presence of the DVA. Subsequently, the normal form of the Hopf bifurcation for the coupled system near the onset of galloping is derived to characterize the type of instability (supercritical or subcritical), while evaluating the effects of the DVA parameters. The results show that with appropriate parametric values, the DVA has great impact on the onset speed of galloping and can significantly alleviate the oscillation amplitude of the prism.

scholarly journals Design and Experimental Implementation of a Beam-Type Twin Dynamic Vibration Absorber for a Cantilevered Flexible Structure Carrying an Unbalanced Rotor: Numerical and Experimental Observations

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Abdullah Özer ◽  
Mojtaba Ghodsi ◽  
Akio Sekiguchi ◽  
Ashraf Saleem ◽  
Mohammed Nasser Al-Sabari
Keyword(s):  
Rotor System ◽  
Operating Conditions ◽  
System Response ◽  
Flexible Structure ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Element Analysis ◽  
Dynamic Vibration ◽  
Unbalanced Rotor ◽  
Beam Type

This paper presents experimental and numerical results about the effectiveness of a beam-type twin dynamic vibration absorber for a cantilevered flexible structure carrying an unbalanced rotor. An experimental laboratory prototype setup has been built and implemented in our laboratory and numerical investigations have been performed through finite element analysis. The proposed system design consists of a primary cantilevered flexible structure with an attached dual-mass cantilevered secondary dynamic vibration absorber arrangement. In addition, an unbalanced rotor system is attached to the tip of the flexible cantilevered structure to inspect the system response under harmonic excitations. Numerical findings and experimental observations have revealed that significant vibration reductions are possible with the proposed dual-mass, cantilevered dynamic vibration absorber on a flexible cantilevered platform carrying an unbalanced rotor system at its tip. The proposed system is efficient and it can be practically tuned for variety of design and operating conditions. The designed setup and the results in this paper can serve for practicing engineers, researchers and can be used for educational purposes.

scholarly journals Vibration absorber optimization for boom-sprayer

2019 ◽  
Vol 27 (4) ◽  
pp. 504-515
Author(s):  
Ivan Kernytskyy ◽  
Serhii Baranovych ◽  
Serhii Berezovetskyi ◽  
Bohdan Diveyev ◽  
Orest Horbay ◽  
...  
Keyword(s):  
Optimal Design ◽  
System Modeling ◽  
Design System ◽  
Vibration Absorber ◽  
Base System ◽  
Main Task ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers

The main task of this work is to analyze optimal design-system of the booms of boom-sprayers. The discrete-continue models of machines dynamics of such wheeled machines as boom-sprayer with elongated boom element with the attachment of dynamic vibration absorbers are offered. The algorithms for vibration decreasing of boom are received. The new vibroabsorbing elements are proposed. The paper contemplates the provision of dynamic vibration absorbers (DVA) of buffered impact masses and particle type. Such originally designed absorbers reduce vibration selectively in maximum vibration mode, without introducing vibration in other modes. The damping results from the exchange of momentum during impacts among the masses and masses and stops as the structure vibrates. A technique is developed to give the optimal DVA’s as single degree of freedom (SDOF) buffered system. The one-digit values are established not only for the dynamic vibration absorber parameters, but also for mechanical parameter of base structure – boom in connection points of the dynamic vibration absorbers. Finally, present research develops the genetic algorithms for optimal design searching by discrete-continuum DVA’s system – base system modeling.

Optimization design for multiple dynamic vibration absorbers on damped structures using equivalent linearization method

2021 ◽  
pp. 146441932110535
Author(s):  
Vu Duc Phuc ◽  
Van-The Tran
Keyword(s):  
Linearization Method ◽  
Equivalent Linearization ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Optimal Parameters ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers ◽  
Equivalent Linearization Method ◽  
Primary Structures

The dynamic vibration absorber and tuned mass damper are widely used to suppress harmful vibration of the damped structures under external excitation. The multiple dynamic vibration absorbers have more benefit than the single dynamic vibration absorber. The multiple dynamic vibration absorbers are portability and easy to install because its size is significantly reduced compared to an individual damper. This paper proposes a design method to obtain optimal parameters of multiple dynamic vibration absorbers attached on damped primary structures by using the least squares estimation of equivalent linearization method. An explicit expression of damping ratio and tuning parameters of multiple dynamic vibration absorbers are determined for minimizing the maximum displacement of the primary structures based on the fixed-point theory. The new contribution is provided a reliable theoretical basis for optimizing parameters of the multiple dynamic vibration absorbers that are attached on the damped primary structures. The numerical results reveal the effectiveness of the proposed optimal parameters of multiple dynamic vibration absorbers in reduce vibration of damped primary structures. In the practical applications, this research results allow to divide a large dynamic vibration absorber into many equivalent small dynamic vibration absorbers, which are convenient for manufacturing and installing on the damped primary structures such as high buildings and cable-stayed bridges.

Sign in / Sign up

Export Citation Format

Share Document