aITM University of Stuttgart
bSapienza University of Rome
Abstract :
The acoustic guitar is a popular string instrument in which the sound
results from a coupled mechanical process. The oscillation of the
plucked strings is transferred through the bridge to the body which
acts as an amplifier to radiate the sound of the guitar. In this
contribution, the vibration of a guitar and the coupling between the
strings and the guitar body is examined experimentally and by means
of numerical simulation. An experimental setup not only capable of
determining eigenmodes and eigenfrequencies but also
demonstrating the transient coupling between the strings and the
body is presented. This capability is achieved with a plucking
mechanism that allows realistic and reproducible plucks of a single
string and synchronized measurements of multiple plucks at different
positions of the guitar body using a scanning laser Doppler
vibrometer. Besides the experimental setup, a finite element model of
the guitar is developed. The numerical model consists of the strings,
the body, and the neck of the guitar. Furthermore, the struts
reinforcing the soundboard and the back of the guitar are included. A
comparison between the numerical model and the experimental
measurements is conducted with particular focus on the transient
coupling between the strings and the soundboard.