Pengaruh Pelepasan Tegangan Sisa dengan Metode Getaran terhadap Frekuensi Nada Dasar Bilah Perunggu Gamelan
Abstract: Bronze is the
material that is usually used to make
musical instruments. Unfortunately, it’s known that the tone of some
instruments will change after several times of usage, like in gamelan. The
theory that underlies the change of the tone is residual stress. Residual
stress is resulted from some forging
activities during the production of gamelan. The objective of this research is
to prove that the residual stress release will affect the change of the tone
frequency of bronze; therefore, the change of the tone frequency of gamelan could
be known.
Experimental analysis was
employed to prove
the hypothesis. The
specimens consisted of
three beams of forged bronze. The
residual stress was released from the beams by vibratory stress release method and the
change of the
tone frequency was
measured. The amount
of residual stress
was measured at the
beginning and at the end of the vibratory treatment with neutron diffraction
method.
The result showed that the tone frequency increased after the residual
stress was released. The tone frequency changed
1 Hz for non-reduction specimen. While the 30% thickness reduction and
50% reduction changed 1 Hz
and 3.5 Hz
in frequency. Residual
stress measurement showed
that the residual
stress decreased after vibratory stress release. The average reduction
of residual stress could attain 39,6% for nonreduction specimen,
69,9% for 30%
thickness reduction specimen
and 81% for
50% thickness reduction specimen. It could be concluded
that the change in gamelan tone caused by residual stress.
Penulis: Ari Wibowo, Sukoco
Kode Jurnal: jptmesindd130263
