High Damping Characteristics of an Elastomer
Particle Damper
Marcelo Bustamante, Samir N. Y. Gerges and Erasmo F. Vergara
Federal University of Santa Catarina, Department of Mechanical Engineering, Laboratory of Vibration and Acous-
tics, Campus Universitario, P.B. 476, Trindade, Florianopolis, SC, CEP 88040-900, Brazil
Jorge P. Arenas
Institute of Acoustics, University Austral of Chile, PO Box 567, Valdivia, Chile
(Received 16 September 2014; accepted 14 December 2015)
Research testing has led to the development of an Elastomer Particle Damper (EPD), which can add considerable
damping to a structure by directing the vibration to a set of interacting elastomer particles through a rigid connec-
tion. This vibration treatment presents highly nonlinear behavior that is strongly dependent on both the vibration
amplitude and frequency. Curves of damping loss factor (DLF) of an EPD system with vertical motion as a func-
tion of frequency and acceleration are reported herein. The results show that the elastomer particle damper has
two distinct damping regions. The first region is related to the fluidization state of the particles, as described in
the literature, obtained when the damper is subjected to vertical acceleration close to 1 g and frequencies below 50
Hz. The second region presents high values of DLF to acceleration values lower than 1 g, and the frequency range
is dependent upon the stiffness of the particles. A high degree of effectiveness is achieved when the working fre-
quency of the elastomer particle dampers is tuned to a natural frequency of a plate and when they are strategically
located at points having large displacement. The performance of EPDs was compared with that of a commercial
constrained layer damping installed in an aircraft floor panel. The EPDs achieved an acceleration level attenuation
in the aircraft floor panel similar to that of the commercial constrained layer damping system.
1. INTRODUCTION
Traditional damping treatments use viscoelastic materials to
convert strain energy into heat energy through the relative in-
ternal motion between molecules. Energy dissipation can be
provided to a vibrating structure by a constrained damping
layer in which a viscoelastic material is sandwiched between
the structure to be damped and a stiff metal layer. Then, bend-
ing of the composite produces shear and the mechanical en-
ergy is dissipated in the middle layer as heat. These materials
have been used quite successfully to address problems of noise
and vibration control.
1
However, the temperature sensitivity in
polymer-damping processes is a major disadvantage.
2
Another
drawback is that the damper properties are strongly dependent
on frequency and strain.
As an alternative, the use of particle dampers (PDs) can be
an interesting solution. PDs are stiff enclosures containing
a large number of either elastic or viscoelastic particles (e.g.
sand, ball bearings, and elastomer balls) as shown in Fig. 1.
Damping performance of PDs is usually not strongly temper-
ature dependent and thus they can be used in harsh environ-
ments. Several studies have been carried out on PDs, mainly
with metal spheres, providing modeling and experimental re-
sults.
3–7
However, in this study, elastomer particles were used
because the interaction between them is quieter, which is an
important aspect in noise and vibration control.
PDs can be added to a structure in two ways: 1) by attach-
ing an enclosure to an exterior surface or 2) by partially filling
manufactured or pre-existing voids inside the structure with
Figure 1. Schematic diagram of a particle damper.
particles.
The operating principle of PDs is based on energy dissipa-
tion through multiple inelastic collisions, interparticle friction,
and friction between the particles and the walls of the con-
tainer. The resulting system is highly nonlinear. Its damping
capacity is greatly dependent on the level of acceleration which
the container undergoes. There are a significant number of
parameters affecting the damper performance. These include
particle size, shape, number and density, the size and shape of
the enclosure, and the properties that affect the particle-particle
and particle-enclosure interactions, such as the coefficients of
friction and restitution.
3
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http://dx.doi.org/10.20855/ijav.2016.21.1401 (pp. 112121) International Journal of Acoustics and Vibration, Vol. 21, No. 1, 2016