Research of Acoustic Metamaterials at the University of Szeged …
491
Fig. 9 Frequency Response Function of an experimental system [13]
frequency ranges where the amplitude decreases are narrow, with steep changes of
the amplitude, while with non-linear springs the frequency ranges are wider, and the
vibration is reduced in a broader frequency range (see Fig. 9).
3 Measuring the Reduction of Vibration
of a 2-Degree-of-Freedom Subsystem
During the experiments a 2-Deggree-Of-Freedom vibration system is investigated
(see Figs. 10, 11) first. This mass-in-mass arranged system represents the subsystem
of the searched metamaterials, so these measurements and calculations are the
simplest. By these investigations the differences between the theoretical calculations
and the measured results were studied. Since the presence (mass) of the used instruments (force transducer, accelerometers) influences the results of the measurements
further work on corrections of the measure results is still needed.
Fig. 10 Model of Two-Degree-Of-Freedom, mass-in-mass arranged vibrating system
491
Fig. 9 Frequency Response Function of an experimental system [13]
frequency ranges where the amplitude decreases are narrow, with steep changes of
the amplitude, while with non-linear springs the frequency ranges are wider, and the
vibration is reduced in a broader frequency range (see Fig. 9).
3 Measuring the Reduction of Vibration
of a 2-Degree-of-Freedom Subsystem
During the experiments a 2-Deggree-Of-Freedom vibration system is investigated
(see Figs. 10, 11) first. This mass-in-mass arranged system represents the subsystem
of the searched metamaterials, so these measurements and calculations are the
simplest. By these investigations the differences between the theoretical calculations
and the measured results were studied. Since the presence (mass) of the used instruments (force transducer, accelerometers) influences the results of the measurements
further work on corrections of the measure results is still needed.
Fig. 10 Model of Two-Degree-Of-Freedom, mass-in-mass arranged vibrating system