Research of Acoustic Metamaterials
at the University of Szeged, Faculty
of Engineering
Péter Szuchy
Abstract Protection against dangerous and harmful vibration is an urgent problem
all around the world. Considerable efforts are in progress for researching and developing acoustic metamaterials. One of these acoustic materials’ working principles is
the mass-in-mass subsystem that is an improved version of the 2-degree-of Freedom
system of dynamic reduction of vibration. The main goal of this paper is to introduce the actualities of practical research work on this field of the University of
Szeged, Faculty of Engineering. First a short review of the theory is summarized,
presenting effective mass, differences between linear and non-linear spring characteristics, results of rotating vector solution. The paper highlights the author’s theory
of the 5-degree-of-freedom subsystem of the “wall-paper”—like acoustic material.
Then it shows the research instruments with the experimental system. It reveals the
gap between the theory and the research results and features the present problems
of the research, bringing into focus the practical side of it. It shortly introduces the
used simulation software that reduces the number of the experiments. The other goal
of this paper is to display the present state of the author’s last year began PhD work
and the planned further steps.
1 Introduction of the Theory
Significant part of acoustic vibrations has harmful impact, either it is a large energy
vibration, like an earthquake, or a small one like a vibration in a car. However the
most frequently occurring dangerous vibration is the noise that surrounds us almost
all day. Its harmful effect in milder case can be only tiredness, stress, but in increased
case it can bring high blood pressure, indigestion, or it can lead even to hearing
loss. One method of the protection against noise is putting insulation between the
source and the receiver, but the mass of it multiplied exponentially by increasing the
noise-insulating ability. For example to improve the efficiency with 30 dB, the mass
P. Szuchy (B)
Faculty of Engineering, University of Szeged, Mars Sqr. 7, 6724 Szeged, Hungary
e-mail: szpeter@mk.u-szeged.hu
© Springer Nature Switzerland AG 2021
N. Herisanu and V. Marinca (eds.), Acoustics and Vibration of Mechanical
Structures—AVMS 2019, Springer Proceedings in Physics 251,
https://doi.org/10.1007/978-3-030-54136-1_49
485
at the University of Szeged, Faculty
of Engineering
Péter Szuchy
Abstract Protection against dangerous and harmful vibration is an urgent problem
all around the world. Considerable efforts are in progress for researching and developing acoustic metamaterials. One of these acoustic materials’ working principles is
the mass-in-mass subsystem that is an improved version of the 2-degree-of Freedom
system of dynamic reduction of vibration. The main goal of this paper is to introduce the actualities of practical research work on this field of the University of
Szeged, Faculty of Engineering. First a short review of the theory is summarized,
presenting effective mass, differences between linear and non-linear spring characteristics, results of rotating vector solution. The paper highlights the author’s theory
of the 5-degree-of-freedom subsystem of the “wall-paper”—like acoustic material.
Then it shows the research instruments with the experimental system. It reveals the
gap between the theory and the research results and features the present problems
of the research, bringing into focus the practical side of it. It shortly introduces the
used simulation software that reduces the number of the experiments. The other goal
of this paper is to display the present state of the author’s last year began PhD work
and the planned further steps.
1 Introduction of the Theory
Significant part of acoustic vibrations has harmful impact, either it is a large energy
vibration, like an earthquake, or a small one like a vibration in a car. However the
most frequently occurring dangerous vibration is the noise that surrounds us almost
all day. Its harmful effect in milder case can be only tiredness, stress, but in increased
case it can bring high blood pressure, indigestion, or it can lead even to hearing
loss. One method of the protection against noise is putting insulation between the
source and the receiver, but the mass of it multiplied exponentially by increasing the
noise-insulating ability. For example to improve the efficiency with 30 dB, the mass
P. Szuchy (B)
Faculty of Engineering, University of Szeged, Mars Sqr. 7, 6724 Szeged, Hungary
e-mail: szpeter@mk.u-szeged.hu
© Springer Nature Switzerland AG 2021
N. Herisanu and V. Marinca (eds.), Acoustics and Vibration of Mechanical
Structures—AVMS 2019, Springer Proceedings in Physics 251,
https://doi.org/10.1007/978-3-030-54136-1_49
485