LAUSR

A Finite-Difference Model of a grand piano soundboard including internal damping is used to estimate the influence of the damping on the vibration of the soundboard. Theoretically, the increase of damping reduces eigenmodes and leads to forced oscillation patterns. Those patterns show considerable dependency of their vibrational shapes upon the driving point. In the extreme case of a heavy damping, the wave starting at the driving point does not reach the boundaries of the soundboard with much strength and is therefore not reflected. Then no eigenmodes exist anymore and the plate behaves like an infinite plate. In the other extreme of a soundboard not damped at all the eigenmodes of the soundboard clearly appear. The measured patterned of a soundboard are compared to the modeled ones and conclusions are derived in terms of the amount of damping in a real soundboard.