Motion of a piano string: Longitudinal vibrations and the role of the bridge
Nicholas J. Giordano, A. J. Korty · The Journal of the Acoustical Society of America · 1996
Using strain gauges as a tool, new results have been obtained for the amplitude of the vibrations of the bridge and soundboard of a piano. These results should prove valuable for the construction of theoretical models of the role of the soundboard in sound production. In addition, they indicate that longitudinal string vibrations, i.e., the stretching and compressing of the string, make a very important contribution to the initial sound signal. The amplitude of this longitudinal motion is a nonlinear function of the transverse vibration amplitude. The mechanism by which the longitudinal vibrations couple to the bridge motion has also been considered.