In the civil engineering field, vibration control devices are ever more required to face dynamic excitation. Design optimization of a damped hybrid vibration absorber. Simple vibration problems with matlab and some help. Determine the parameters of the vibration absorber what will reduce the vibration when mounted on the pedestal.
Dynamic vibration absorbers can be used for passive control of narrowband vibration. A sinusoidal steady state solution can be derived for. Damped vibration refers to the gradual or exponential reduction of vibration through resistance of the vibrational forces or by damping as the term indicates as against free vibration. Working pressure psi standards 1 12 of 16 1 12 of 16.
Parameters optimization for a kind of dynamic vibration. Damped vibration absorber wood group anti vibration products wood groups damped vibration absorber dva is a tuned mass damper solution for resonancerelated vibration problems. This absorber is primarily to reduce wind induced motion. Vibration levels, as a result of wave action, were reduced by a factor of approximately six.
Pdf design of nontraditional dynamic vibration absorber for. Figure 2 shows a different way to attach a damper to the absorber mass. In the following table and figures the response of the general linear dynamic vibration absorber is. Pdf design optimization of a damped hybrid vibration. Three fixed points are found in the amplitudefrequency curves of the primary system. The beam that acts as onesided stiffness, is modelled as a massless spring. Sea trials of a damped vibration absorber installed on a 550 tonne ship are described.
In the absence of damping, the equation of motion in free vibration is m y. The vibration absorber 1, also called dynamic vibration absorber dva, is a mechanical device used to reduce or eliminate unwanted vibration. The dva is best suited for reducing vibration with fixedfrequency forcing functions, but in some cases can also help with variablefrequency vibration. Optimal design of a damped dynamic vibration absorber for. Alternately, a dut device under test is attached to the table of a shaker. Vibration testing is accomplished by introducing a forcing function into a structure, usually with some type of shaker. Dynamic vibration absorber is an ideal device for vibration control at specific frequencies. The theory of a continuous damped vibration absorber to. You create a mfile using a text editor and then use them as you would any other matlab function or command. As a benchmark problem, a plate incorporating multiple. Undamped vibration absorber forced damped vibration absorber. Simple vibration problems with matlab and some help from maple. Sep 01, 20 response of a viscous damped structure supported on a foundation subjected to harmonic vibration equation off motion 16.
Different from the conventional way, the dva damper is connected between the absorber mass and the ground. First four eigenmodes of the beam system without the onesided stiffness. We analyzed vibration of several conservative systems in the preceding section. The first approach solves a set of nonlinear equations established by the chebyshevs. The dynamic vibration absorber was invented in 1909 by dynamic vibration absorbers application with variable speed machines yuri khazanov, p. You can express m 2 and k 2 in terms of parameters m and k.
Selftuning dynamic vibration absorber for machine tool chatter. Common experience indicates that real oscillators behave somewhat differently, however. When the wdra of vibration is a force acting on the objeut, the rqspoose mp1itude is awmf,k wthe soura is dieplaoansa with amptttude x, the respom anlplitmia is a tx, when 6 m the asacarbly is h monana d the mpome ampli tude bec large infinite in terms of the undampcd model. The absorber was designed to increase the damping in the fundamental vertical bending mode of the ship. Thompson 2007 considered a massspring absorber system to. The results show that maximum vibration suppression and energy harvesting objectives occur for nearly the same load resistance in the harvester circuit. Nonlinear magnetic vibration absorber for passive control of a multi. But before using the user defined functions always make sure that the path is set to the current directory.
Application of a dynamic vibration absorber 229 figure 2. Introduction to vibration control pvlethods of vibration control vibration isolation rigidly coupled viscous damper elastically coupled viscous damper undannped vibration absorber forced damped vibration absorber. Other articles where damped vibration is discussed. The resulting damped vibration absorber is sometimes called a tuned mass damper. Analysis of parallel damped dynamic vibration absorbers journal. In order to get a robust vibration control performance. A mass of 30 kg is supported on a spring of stiffness 60 000 nm. While tuned vibration absorbers have been widely applied for damping of. These are variously called tuned vibration absorbers, dynamic vibration. Solving problems in dynamics and vibrations using matlab. Dynamic vibration absorbers application with variable speed. The engine induces vibration through its pedestal mount at an operating speed of 6000 rpm. The oscillations may be periodic, such as the motion of a pendulumor random, such as the movement of a tire on a gravel road vibration can be desirable. In an undamped or lightly damped system when the excitation frequency nears the natural frequency the amplitude of the vibration can get extremely high.
M files files that contain code in matlab language are called m files. Unlike traditional dva configurations, the damping element in this type of dva is connected directly to the ground instead of the primary mass. Tuning of a piezoelectric vibration absorber attached to a damped structure soltani, p. Passive distributed vibration absorbers for low frequency. Modelling of a sdof system with dynamic vibration absorber dva. It consists of auxiliary system attached to the main system that needs to be protected from excessive vibration. If resonance occurs in a mechanical system it can be very harmful leading to eventual failure of the system. Tuned mass absorber, tmd, random vibration, structural dynamics abstract. Optimum design of damped dynamic vibration absorber a. Matlab matrix laboratory was born from the linpack routines written for use with c and fortran. Damped dynamic vibration absorber by adding viscous damping c to the absorber system, a better attenuation in a wide frequency range can be achieved. In the classical theory of dva, it has been shown that when a damped vibration absorber is attached to a undamped singledegreefreedom system, there exist two frequencies at which the amplitudes of the esponse of the main r. An example of this type of vibration is the vehicular suspension dampened by the shock absorber.
At first, the analytical solution of the system is obtained based on the established differential motion equation. Since the dva was not tuned to all of the modes that. Magnetostrictive dynamic vibration absorber dva for passive and active damping. Pdf dynamic vibration absorbers and its applications.
Pdf the voigttype of dynamic vibration absorber is a classical model and has attracted considerable attention in many years because of its simple. The design formulae for the optimum tuning ratio and optimum stiffness ratio of dva are obtained by. Vibration analysis of a horizontal washing machine, part. The basic principle of operation is vibration out of phase with the vibration of such structure, thereby applying a. Shortcommunication thedampeddynamicvibrationabsorbers. Nayfeh,minimaxoptimizationofmultidegreeoffreedomtunedmassdampers,journal of sound and vibration 2722004893908.
The documents may come from teaching and research institutions in france or abroad, or from public or private research centers. Pdf vibration absorbers are mainly used in civil engineering structures, e. A relatively small amount of damping is needed to reduce vibration at the two natural frequencies. As described in the classical textbooks on dynamic vibration absorber,, an undamped dynamic vibration absorber is an auxiliary massspring system which, when correctly tuned and attached to a vibrating body subject to a harmonic excitation, eliminates steadystate motion of the point to which it is attached. To write its equations of motion, we add the appropriate damping terms to 1 and obtain.
For best effect, a damped dva should be optimized so. A watch balance wheel submerged in oil is a key example. A study on the application of tuned vibration absorbers to nominally cyclic. The use of dynamic vibration absorbers to control the vibration of a structure in both narrow and broadbands is discussed in this paper. They applied two numerical approaches by solving a set of nonlinear. Description of the device the nonlinear vibration absorber is shown in fig. Introduction vibrational energy harvesting aims to convert ambient. Damped vibration absorber wood group antivibration products wood groups damped vibration absorber dva is a tuned mass damper solution for resonancerelated vibration problems. Analysis of parallel damped dynamic vibration absorbers. The theory of a continuous damped vibration absorber to reduce.
Application of a dynamic vibration absorber to a piecewise. Application case of deterministic linear dynamic vibration absorber the numerical calculation table has been developed with the aid of spreadsheet program excel 4. Tuning of a piezoelectric vibration absorber attached to a. The effect of the mass dynamic vibration absorber is dependent on the ratio of its mass.
When the wdra of vibration is a force acting on the objeut, the rqspoose mp1itude is awmf,k wthe soura is dieplaoansa with amptttude x, the respom anlplitmia is a tx, when 6 m the asacarbly is h monana d the mpome ampli tude bec large infinite in terms of. They have applied brocks approach to different type of damped vibration absorber named model b when the main system is damped and the absorber damper is connected to the ground and found its optimal parameters 2. The word comes from latin vibrationem shaking, brandishing. Pennestri, an application of chebyshevs minmax criterion to the optimum design of a damped dynamic vibrationabsorber,journal of sound and vibration 2171998757765. A new type of dynamic vibration absorber dva with negative stiffness is studied in detail. Lin and coppola 2010 studied the optimal design of the damped dynamic vibration absorber for damped primary systems. The vibration absorber1, also called dynamic vibration absorber dva, is a mechanical device used to reduce or eliminate unwanted vibration. For example, we have shock absorbers in bikes if they are. In each case, we found that if the system was set in motion, it continued to move indefinitely.
The results are given in tabular format in table 4. This catalog is intended to provide you with a basic background on vibration control theory and specific vibration and shock control solutions. Optimizations of distributed dynamic vibration absorbers for. From an analytical point of view, models of vibrating systems are commonly divided into two broad classes discrete, or lumpedparameter models, and continuous, or distributedparameter models. Vibration analysis of a horizontal washing machine, part iv. Forced damped motion real systems do not exhibit idealized harmonic motion, because damping occurs. Concurrent attenuation of, and energy harvesting from. Vibration isolation the force transmitted to the foundation is the sum of the spring force and the damper force. The magnitude of the exciting force is 250 n, and the amplitude of motion of the absorber mass is to limited to 2 mm. The purpose of optimal tuning of a damped vibration absorber is to minimize the steadystate amplitude of the primary mass over the entire range of driving frequency. This study focuses on the optimum design of the damped dynamic vibration absorber dva for damped primary systems. A study on the application of tuned vibration absorbers to. The simple harmonic oscillations discussed above continue forever, at constant amplitude, oscillating as shown in figure 3 between a and.
A detailed analysis of the frequency response properties of the tuned mass absorber has recently been pre. Response of a viscous damped structure supported on a foundation subjected to harmonic vibration equation off motion 16. Vibration of damped systems aeng m2300 4 developed for undamped systems, can be used to analyze damped systems in a very similar manner. Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. This leads to an absorber tuning schedule as follows. By the use of this technique, one can achieve reduction in vibration in an easier and economical way. The application of dynamic vibration absorbers is especially effective for high slender constructions. Dynamic vibration absorbers application with variable. Nonlinear vibration absorber and the measured free vibration 2. The work includes simple clamping technique with the rail along the line. They used genetic algorithm to optimize the best absorber model 5.
411 115 1572 141 361 687 1538 1476 1302 1522 440 984 1115 1261 850 1000 1180 1510 571 1513 579 721 509 1247 1254 49 1311 662 778 711 1092 1294 61 443 523 483 625 208 392 682 812