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| Resonance Decrease |
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Structural
damping is the effect of internal friction within changing a
material vibration energy into heat. This reduces excessive noise
and vibration by converting them into heat to be expelled into the
surrounding area.
Vibration
energy in cellular structures is dissipated by the slight plastic
deformation of the thin walls separating the pores. It can also be
reduced by friction between the surfaces of cracks appearing in the
pore walls. |
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| Alulight®
rod-shaped specimens (Ø 17mm, lenght min. 300mm) with various
densities and pore sizes were used to test the material. |
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| Loss factor of a solid
Aluminum-tube, a Alulight® rod filled Aluminium-tube at
different resonant frequencies.
Test Method:
a rod-shaped specimen of Alulight was
excited in longitudinal vibration by the" impact
hammer" method. The amplitude decay was measured by the
miniature piezoelectric accelerator.
Trial Sample:
Al-tube
(Ø 18mm, wall thickness 1 mm, length 450 mm)
Alulight(Ø
17mm, length 450 mm, density 530 kg/m3) |
| Summary
of Results: |
Main
Applications: |
- The
loss factor of Alulight® is one order higher than the loss
factor of Aluminium
- loss
factor of the material tested (AISiMg, AISi12)
seems to have a maximum at densities around 630 kg/m3
- damping
ability of Alulight® depends insignificantly on resonant
frequency
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- structural
material for various cases gear boxes or covers which suffer
from mechanical vibrations
- damping
material to fill hollow parts or profiles
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