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Optimal configuration and parameters of translational dynamic vibration absorbers in vibroisolation of mechanical press

Łatas Waldemar, Dziechciowski Zygmunt

Vibrations in Physical Systems

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2020

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Vol. 31, nr 3

art. no. 2020314

EN

The paper deals with the problem of optimizing the positions and parameters of dynamic vibration absorbers for a mechanical press subjected to polyharmonic inertial excitation. Under the assumption of small vibrations a linear dynamic model of a rigid body performing a planar motion, on viscoelastic supports, with an attached system of translational tuned mass dampers is constructed. The problem of vibroisolation of the machine is presented, considering selected harmonics of the force transmitted to the ground, the solutions with a single DVA are proposed.

2

Effect of inerter in traditional and variant dynamic vibration absorbers for one degree-of-freedom systems subjected to base excitations

Barathwaaj Dheepakram Laxmimala, Yegateela Sujay, Vardhan Vivek, Suresh Vignesh, Kaliyannan Devarajan

Mechanics and Mechanical Engineering

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2019

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Vol. 23, nr 1

9--16

EN

In this paper, closed-form optimal parameters of inerter-based variant dynamic vibration absorber (variant IDVA) coupled to a primary system subjected to base excitation are derived based on classical fixed-points theory. The proposed variant IDVA is obtained by adding an inerter alone parallel to the absorber damper in the variant dynamic vibration absorber (variant DVA). A new set of optimum frequency and damping ratio of the absorber is derived, thereby resulting in lower maximum amplitudę magnification factor than the inerter-based traditional dynamic vibration absorber (traditional IDVA). Under the optimum tuning condition of the absorbers, it is proved both analytically and numerically that the proposed variant IDVA provides a larger suppression of resonant vibration amplitude of the primary system subjected to base excitation. It is demonstrated that adding an inerter alone to the variant DVA provides 19% improvement in vibration suppression than traditional IDVA when the mass ratio is less than 0.2 and the effective frequency bandwidth of the proposed IDVA is wider than the traditional IDVA. The effect of inertance and mass ratio on the amplitude magnification factor of traditional and variant IDVA is also studied.

3

Application of the continuous dynamic absorbers in local and global vibration reduction problems in beams

Łatas W.

Vibrations in Physical Systems

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2016

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Vol. 27

245--254

EN

The paper deals with the application of the continuous dynamic absorbers in vibration reduction problems in beams. The Euler-Bernoulli beam of variable cross-section is subjected to the concentrated and distributed harmonic excitation forces. The beam is equipped with a system of the continuous vibration absorbers. The problem of the forced vibration is solved employing the Galerkin’s method and Lagrange’s equations of the second kind. Performing time-Laplace transformation the amplitudes of displacement may be written in the frequency domain, similarly the time-averaged kinetic energy of any part of the beam. The results of some local and global vibration control optimization problems concerning the placement and parameters of the continuous vibration absorbers are presented.

4

Multiple tuned tunable translational-rotational vibration absorbers in beam

Łatas W.

Vibrations in Physical Systems

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2014

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Vol. 26

145--152

EN

The paper deals with vibration of the beam with a system of the translational-rotational dynamic vibration absorbers attached. The beam is subjected to the distributed and concentrated harmonic excitation forces. Assuming small and linear vibration, an analytical Euler-Bernoulli model is applied and the solution to the problem is found with the use of Fourier method. Performing time-Laplace transformation the displacement amplitude of arbitrary point of the beam may be written in the frequency domain. The aim of the paper is to investigate the improvement of the efficiency of the translational-rotational absorbers compared with the translational ones in global vibration control problems. As an example reduction of the kinetic energy of the host structure is considered. Numerical simulations shows a considerable improvement of vibration reduction when the translational-rotational absorbers are utilized.

5

Distributed dynamic vibration absorber in beam

Łatas W.

Vibrations in Physical Systems

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2014

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Vol. 26

137--144

EN

The paper deals with forced vibration of Euler-Bernoulli beam with variable cross-section equipped with a distributed dynamic absorber. The beam is subjected to the concentrated and distributed harmonic excitations. The problem is solved using Galerkin’s method and Lagrange’s equations. Performing time-Laplace transformation the displacement amplitude of arbitrary point of the beam may be written in the frequency domain. The aim of the paper is to find the effectiveness of the distributed vibration absorbers in beams. As an example numerical results of vibration reduction in wind turbine’s tower are presented.