scholarly journals A Simple Method to Design and Analyze Dynamic Vibration Absorber of Pipeline Structure Using Dimensional Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Mehrdad Shemshadi ◽  
Mahdi Karimi ◽  
Farzad Veysi
Keyword(s):  
Dimensional Analysis ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Harmonic Excitation ◽  
Vibration Absorber ◽  
Concentrated Mass ◽  
Dynamic Vibration Absorber ◽  
Simple Method ◽  
Dynamic Vibration ◽  
Pipe Vibration

Vibrations due to mechanical excitation and internal and external fluid flow can cause fatigue in pipelines and leaks in fittings. A beam-based dynamic vibration absorber (beam DVA) is a device comprising an L-shaped beam with a concentrated mass at its free end that can be used to absorb and dissipate vibrations in the pipeline. In this paper, a mathematical equation is extracted to design the beam DVA using the dimensional analysis (DA) method and data recorded from 120 experimental tests. In the experimental studies, the pipes are fabricated in 1-inch, 2-inch, and 3-inch sizes. Each pipe is subjected to harmonic excitation at different frequencies, and the amplitude of vibration of the pipe is evaluated by changes in the geometric characteristics of beam DVA and concentrated mass. The proposed methodology is validated using the finite element method and simulation in the SIMULINK/MATLAB. The results showed that, out of the nine effective dimensionless parameters identified in pipe vibration control, mass ratio and stiffness ratio have the highest and lowest impacts on pipe vibration absorption, respectively.

A simple method to design and analyze dynamic vibration absorber using dimensional analysis

2020 ◽  
pp. 107754632092392
Author(s):  
Mahdi Karimi ◽  
Mehrdad Shemshadi ◽  
Naghmeh Firoozfam
Keyword(s):  
Dimensional Analysis ◽  
Numerical Solutions ◽  
Vibration Absorber ◽  
Linear Regression Method ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Simple Method ◽  
Dynamic Vibration ◽  
Analysis Technique ◽  
Mass Spring

Addition of mass, spring, and damper as a dynamic vibration absorber to a structure that is vibrating out of the permissible vibration range can be an economic and applicable solution to reduce structure vibrations provided that the absorber is designed and adjusted properly. In practice, real structures are damped, which can make it impossible to design vibration absorbers without using numerical solutions and complicated calculations. Using dimensional analysis technique and data obtained from system simulation by MATLAB Simulink, this study aims to provide simple and reliable correlations for designing and analyzing vibration absorbers. For this purpose, the motion equations of a one-degree-of-freedom system with a vibration absorber and a harmonic force applied is simulated. Use of a set of simulation output data to minimize the maximum motion amplitude of the structure along with multiple linear regression method enables determination of unknown coefficients of the correlations derived from dimensional analysis. Studies show that mass ratio and stiffness ratio are important for designing vibration absorbers for undamped and damped structures, respectively. The correlations are validated using the methods introduced in previous studies. Also, an example of vibration absorbers is calculated for an air compressor. The vibration absorber designed by this methodology results in a reduction in the magnification factor of the compressor by 78%.

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.

Experimental Studies on Dynamic Vibration Absorber using Shape Memory Alloy (NiTi) Springs

2011 ◽  
Author(s):  
V. Raj Kumar ◽  
M. B. Bharathi Raj Kumar ◽  
M. Senthil Kumar ◽  
P. Predeep ◽  
Mrinal Thakur ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Experimental Studies ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration

scholarly journals Optimal parameters of dynamic vibration absorber for linear damped rotary systems subjected to harmonic excitation

2020 ◽  
Author(s):  
Vu Duc Phuc ◽  
Tong Van Canh ◽  
Pham Van Lieu
Keyword(s):  
Vibration Suppression ◽  
Fixed Point Theory ◽  
Damping Ratio ◽  
Harmonic Excitation ◽  
Tuning Parameter ◽  
Vibration Absorber ◽  
Optimal Parameters ◽  
Dynamic Vibration Absorber ◽  
Practical Applications ◽  
Dynamic Vibration

Dynamic vibration absorber (DVA) is a simple and effective device for vibration absorption used in many practical applications. Determination of suitable parameters for DVA is of significant importance to achieve high vibration reduction effectiveness. This paper presents a   method to find the optimal parameters of a DVA attached to a linear damped rotary system excited by harmonic torque. To this end, a closed-form formula for the optimum tuning parameter is derived using the fixed-point theory based on an assumption that the damped rotary systems are lightly or moderately damped. The optimal damping ratio of DVA is found by solving a set of non-linear equations established by the Chebyshev's min-max criterion. The performance of the proposed optimal DVA is compared with that obtained by existing optimal solution in literature. It is shown that the proposed optimal parameters are possible to obtain superior vibration suppression compared to existing optimal formula. Extended simulations are carried out to examine the performance of the optimally designed DVA and the sensitivity of the optimum parameters. The simulation results show that the improvement of the vibration performance on damped rotary system can be as much as 90% by using DVA.

scholarly journals Vibration Control of Time-Varying Delay under Complex Excitation

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1081
Author(s):  
Kaiwei Wu ◽  
Chuanbo Ren ◽  
Yuanchang Chen ◽  
Sujuan Shao ◽  
Jilei Zhou ◽  
...  
Keyword(s):  
Time Delay ◽  
Harmonic Excitation ◽  
Vibration Absorber ◽  
Time Interval ◽  
Control Effect ◽  
Dynamic Vibration Absorber ◽  
Time Varying Delay ◽  
Dynamic Vibration ◽  
Vibration Attenuation ◽  
Varying Delay

The existing available research outcomes on vibration attenuation control for time-delay feedback indicate that, for the delay dynamic vibration absorber with fixed time-delay control parameters, under harmonic excitation, a good vibration attenuation control effect occurs on the vibration of the main system. However, the effect is not obvious for complex excitation. Aiming at the above problems, in a short time interval, a harmonic excitation with the same displacement size as the complex excitation was established. Then, by calculating its equivalent amplitude and equivalent frequency, a harmonic equivalent method for complex excitation was proposed in this paper. The time-delay parameters were adjusted according to the equivalent frequency of harmonic equivalent excitation in real time; therefore, a good vibration attenuation control effect was obtained through the delay dynamic vibration absorber in the discrete time interval. In this paper, research on a time-varying delay dynamic vibration absorber was conducted by taking the two-degree-of-freedom vibration system with a delay dynamic vibration absorber as an example. The simulation results show that the proposed control method can reduce the vibration of the main system by about 30% compared with the passive vibration absorber. This can obviously improve the performance of the time-delay dynamic vibration absorber. It provides a new technical idea for the design of vehicle active frame system.

Parametric Uncertainty and Random Excitation in Energy Harvesting Dynamic Vibration Absorber

2020 ◽  
Author(s):  
M Rajarathinam ◽  
Shaikh Faruque Ali
Keyword(s):  
Energy Harvesting ◽  
Damping Ratio ◽  
Parametric Uncertainty ◽  
Electrical Energy ◽  
Harmonic Excitation ◽  
Random Excitation ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Host Structure

Abstract An energy harvesting dynamic vibration absorber is studied to suppress undesirable vibrations in a host structure as well as to harvest electrical energy from vibrations using piezoelectric transduction. The present work studies the feasibility of using vibration absorber for harvesting energy under random excitation and in presence of parametric uncertainties. A two degrees of freedom model is considered in the analytical formulation for the host along with the absorber. A separate equation is used for energy generation from piezoelectric material. Two studies are reported here, (i) with random excitation where the base input is considered to be Gaussian; (ii) parametric uncertainty is considered with harmonic excitation. Under random base excitation the analytical results show that, with the proper selection of parameters, harvested electrical energy can be increased along with the reduction in vibration of the host structure. Graphs are reported showing trade-off between harvested energy and vibration control. Whereas, Monte Carlo simulations are carried out to analyze the system with parametric uncertainty. This showed that the mean harvested power decreases with an increase in uncertainties in the natural frequency as well as damping ratio. In addition, optimal electrical parameters for obtaining maximum power for the case of uncertain parameters are also reported in this study.

Vibration Control of Plates by Plate-Type Dynamic Vibration Absorbers

1995 ◽  
Vol 117 (3A) ◽  
pp. 332-338 ◽  
Author(s):  
T. Aida ◽  
K. Kawazoe ◽  
S. Toda
Keyword(s):  
Degrees Of Freedom ◽  
Large Scale ◽  
Equations Of Motion ◽  
Harmonic Excitation ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Two Degrees Of Freedom ◽  
Tuning Method ◽  
Dynamic Vibration ◽  
Plate Type

In this paper, a new plate-type dynamic vibration absorber is presented for controlling the several predominant modes of vibration of plate (mainplate) under harmonic excitation, which consists of a plate (dynamic absorbing plate) under the same boundary condition as the main plate and with uniformly distributed connecting springs and dampers between the main and dynamic absorbing plates. Equations of motion of the system in the modal coordinates of the main plate become equal to those of the two-degrees-of-freedom system with two masses and three springs. Formulas for optimum design of the plate-type dynamic vibration absorber are presented using the optimum tuning method of a dynamic absorber in two-degrees-of-freedom system, obtained by the Den Hartog method. Moreover, for practical problems regarding large-scale plates, an approximate tuning method of the plate-type dynamic absorbers with several sets of concentrated connecting springs and dampers is also presented. The numerical calculations demonstrate the effectiveness of the plate-type dynamic absorbers.

Numerical and experimental studies on the car body flexible vibration reduction due to the effect of car body-mounted equipment

2016 ◽  
Vol 232 (1) ◽  
pp. 103-120 ◽  
Author(s):  
Caihong Huang ◽  
Jing Zeng ◽  
Guangbing Luo ◽  
Huailong Shi
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Numerical Study ◽  
Experimental Studies ◽  
Vibration Absorber ◽  
Response Analysis ◽  
Dynamic Vibration Absorber ◽  
Vibration Absorption ◽  
Car Body ◽  
Dynamic Vibration

To study the effect of car body-mounted equipment on the car body flexible vibration, a vertical rigid-flexible coupling model of a high-speed vehicle is established, which includes a flexible car body, rigid bodies for two bogie frames, four wheelsets, and the car body-mounted equipment. The car body is approximated by an elastic beam, with dimensions selected to give similar mass and vertical bending frequency to an existing car body. Model validation is then carried out by comparing results from numerical simulation and on-track test. Using frequency response analysis and ride comfort analysis, parametric studies are undertaken in order to investigate the respective effect of equipment mounting systems on the car body flexible vibration and ride comfort perceived by the passenger. It is found that the equipment behaves as a dynamic vibration absorber on account of its elastic connections to the car body. The stiffness, damping, mass, and installing position of the equipment have a significant influence on the car body flexible vibration. The optimal parameters of the dynamic vibration absorber are given, which can contribute much to the vibration absorption of the car body flexible vibration. Finally, extensive tests on a high-speed test vehicle are conducted to represent a part of results obtained in the numerical study, including modal tests on the car body, component tests on rubber springs used in the equipment mounting systems, and roller rig tests on the vibration absorption performance of the equipment. It is shown that the car body flexible vibration can be effectively suppressed by reasonably suspending the car body-mounted equipment.

Experimental Study on Frequency Band of Dynamic Vibration Absorber in Pipe Systems

2016 ◽  
Author(s):  
Xiufeng Yang ◽  
Lidong He ◽  
Bingkang Zhang
Keyword(s):  
Vibration Suppression ◽  
Single Layer ◽  
Chemical Equipment ◽  
High Mass ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Particle Damping ◽  
New Type ◽  
Pipe Vibration

This paper investigated the vibration control mechanism of dynamic vibration absorber (DVA) used in pipelines and other chemical equipment. For investigating the broadband characteristics, a pipe-vibration absorber test bench was built and different tests were carried out. The results showed that high mass ratio could widen the frequency bandwidth of effective vibration suppression. A new type of passive ring-shaped DVA with particle damping, employing moving steel particles in single-layer or more-layers boxes was designed, and its vibration suppression capability tested and compared with traditional DVA. The proposed damped DVA could reduce the pipeline double vibration peaks typical of the traditional DVAs. Moreover, results showed that stratifying the box was a useful method to improve the vibration suppression efficiency that increased from 59.5% (single-layer-box case) to 72.5% when two-layers-box were used and to 78.5% with three-layers-box.

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