Design of Pendulum Absorbers for Transverse Vibration Attenuation of Rotating Beams

1997 ◽  
Author(s):  
Yenkai Wang ◽  
Steven W. Shaw ◽  
Chang-Po Chao
Keyword(s):  
Transverse Vibration ◽  
Design Strategy ◽  
Simplified Model ◽  
Vibration Absorbers ◽  
Rotating Beam ◽  
External Excitation ◽  
Rotating Beams ◽  
Transverse Vibrations ◽  
Vibration Attenuation ◽  
Centrifugal Pendulum Vibration Absorbers

Abstract This paper considers the placement, sizing and tuning of centrifugal pendulum vibration absorbers for the reduction of transverse vibrations in rotating beams. A simplified model describing the linearized dynamics of a rotating beam with external excitation and attached absorbers is used for the analysis. A design strategy is offered wherein individual absorbers are designed to reduce vibration amplitudes and stress levels caused by troublesome resonances. It is shown that this procedure offers significant reduction in vibratory stresses, even in the case of excitations composed of multiple harmonics.

On the Effects of Imperfections and Mistuning on the Performance of Subharmonic Vibration Absorbers

1997 ◽  
Author(s):  
Chang-Po Chao ◽  
Steven W. Shaw
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Vibration Absorbers ◽  
Performance Indices ◽  
External Excitation ◽  
Rotating System ◽  
Centrifugal Pendulum Vibration Absorbers ◽  
Applicable Range ◽  
Subharmonic Vibration ◽  
Steady State Solutions

Abstract A pair of centrifugal pendulum vibration absorbers (CPVA’s) riding on half-order epicycloidal paths have recently been found to be very effective at reducing torsional vibration levels in a rotating system that is subjected to a harmonic external torque. Previous analyses of this system have assumed perfectly manufactured and exactly tuned paths for the absorber masses. The primary goal of this study is to explore the effects that manufacturing and other imperfections and intentional mistunings have on the performance of this absorber system. To this aim, the equations of motion are first derived for a simplified model. The basic system has two and a half degrees of freedom with a one-to-one internal resonance and two-to-one resonant external excitation. Utilizing the method of averaging, the steady-state solutions are obtained and used to evaluate the absorber performance via two performance indices: the rotor acceleration and the applicable range of the disturbing torque. Finally, some guidelines are provided for designers in terms of how one should choose and/or control intensional mistuning and imperfections of the absorber paths.

The Use of Vibration as a Means of Industrial Drive

1947 ◽  
Vol 157 (1) ◽  
pp. 20-31
Author(s):  
C. A. M. Thornton
Keyword(s):  
Natural Frequency ◽  
Transverse Vibration ◽  
Vibration Amplitude ◽  
Electrical Excitation ◽  
Advantages And Disadvantages ◽  
Transverse Vibrations ◽  
Industrial Drive ◽  
The Subject ◽  
And Control

The application of vibration as a means of industrial drive has been considerably developed in the last twenty years. Starting from the obvious application of screening, it has been extended to conveying, heat interchanging, consolidation of material in packages to reduce shipping space, keeping material “fluid” in hoppers and chutes, hammering, etc. The paper discusses that part of the subject involved in the production and control of the vibration by mechanical or electrical means under all conditions of load. Formulae are developed for calculation of spring strength and for the calculation of the spring dimensions, and for the avoidance of spring fatigue. The various methods of electrical excitation are compared, and the relative advantages and disadvantages are discussed. The desirable instrument equipment is described, including the remote indication of vibration amplitude. A method is outlined by which it is claimed that vibration can be maintained constant at all loads and at any desired frequency. The testing of vibrating drives at the manufacturer's works and on site is discussed. In an Appendix to the paper the problem of transverse vibrations in long vibrating conveyors is treated mathematically, and a formula is developed for the natural frequency of transverse vibration of a conveyor of any uniform section and of any length.

Stiff-String Basis Functions for Vibration Analysis of High Speed Rotating Beams

2008 ◽  
Vol 75 (2) ◽  
Author(s):  
Jagadish Babu Gunda ◽  
Ranjan Ganguli
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Natural Frequencies ◽  
Basis Functions ◽  
Beam Equation ◽  
Rotating Beam ◽  
Rotating Beams ◽  
Centrifugal Stiffening ◽  
Convergence Study ◽  
Stiffening Effect

A new rotating beam finite element is developed in which the basis functions are obtained by the exact solution of the governing static homogenous differential equation of a stiff string, which results from an approximation in the rotating beam equation. These shape functions depend on rotation speed and element position along the beam and account for the centrifugal stiffening effect. Using this new element and the Hermite cubic finite element, a convergence study of natural frequencies is performed, and it is found that the new element converges much more rapidly than the conventional Hermite cubic element for the first two modes at higher rotation speeds. The new element is also applied for uniform and tapered rotating beams to determine the natural frequencies, and the results compare very well with the published results given in the literature.

Torsional Vibration Suppression by a Centrifugal Pendulum Vibration Absorber

2005 ◽  
Author(s):  
Yukio Ishida ◽  
Tsuyoshi Inoue ◽  
Taishi Kagawa ◽  
Motohiko Ueda
Keyword(s):  
Torsional Vibration ◽  
Large Amplitude ◽  
Vibration Suppression ◽  
Torsional Vibrations ◽  
Vibration Absorbers ◽  
Harmonic Vibrations ◽  
Centrifugal Pendulum Vibration Absorbers ◽  
Automobile Engines ◽  
Large Amplitude Vibration ◽  
Driving Torque

Driving torque of rotating machinery, such as automobile engines, changes periodically. As a result, torsional vibrations occur and cause serious noise and vibration problems. In this study, the dynamic characteristics of centrifugal pendulum vibration absorbers restraining torsional vibration is investigated both theoretically and experimentally. In the theoretical analysis, the nonlinear characteristics are taken into consideration under the assumption of large amplitude vibration of pendulum. It is clarified that the centrifugal pendulum, although it has remarkable effects on suppressing harmonic vibration, induces large amplitude harmonic vibrations, the second and third superharmonic resonances, and unstable vibrations of harmonic type. We propose various methods to suppress these secondarily induced vibration and show that it is possible to suppress torsional vibrations to substancially zero amplitude in all through the rotational speed range.

The Transverse Vibration of a Doubly Tapered Beam

1977 ◽  
Vol 44 (1) ◽  
pp. 123-126 ◽  
Author(s):  
D. O. Banks ◽  
G. J. Kurowski
Keyword(s):  
Free Boundary ◽  
Boundary Conditions ◽  
Cross Section ◽  
Transverse Vibration ◽  
Eigenvalues And Eigenfunctions ◽  
Free Boundary Conditions ◽  
Tapered Beam ◽  
Transverse Vibrations ◽  
The Cross ◽  
Homogeneous Beam

We analyze the transverse vibrations of a thin homogeneous beam which is symmetric with respect to the x-y and x-z planes. The cross section of the beam at x is assumed to have the form D(x)={(x,y,z)|x∈[0,1],y=xαy1,z=xβz1,(y1,z1)∈D1} where D1 is the cross section at x = 1. Expressions are obtained from which the eigenvalues and eigenfunctions can be easily found for 0 ≤ α < 2 and all combinations of clamped, hinged, guided, and free boundary conditions at both ends of the beam.

Nonlinear Aspects of the Performance of Centrifugal Pendulum Vibration Absorbers

1964 ◽  
Vol 86 (3) ◽  
pp. 257-263 ◽  
Author(s):  
D. E. Newland
Keyword(s):  
Torsional Vibration ◽  
Large Amplitude ◽  
Vibration Absorbers ◽  
Aircraft Engines ◽  
Reciprocating Engines ◽  
Centrifugal Pendulum Vibration Absorbers ◽  
Large Amplitude Motion

Centrifugal pendulums have been used for many years to limit the torsional vibration of reciprocating engines. Recently small pendulums, designed to swing through amplitudes of about 45 deg, have been tested for lightweight aircraft engines. These have not functioned properly, and have been found to swing through much larger angles than expected, damaging the stops limiting motion of the pendulum counterweight. This paper investigates the large-amplitude motion of centrifugal-pendulum vibration absorbers.

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