About pressure of waves extending in strings of piano on impedance border («bridge»)

We investigate the interaction of the transverse waves in piano string with the string support (bridge), which is considered as an oscillating system consisting of the mass, spring and damper. The part of the string passing the bridge terminates at a point load on a damper. Already in classical papers (J. Rayleigh, J. Larmor, E. Nicolai), it was shown that the elastic waves traveling through various systems transfer with themselves energy and pulse. For this reason the traveling waves exert the pressure on an obstacle. In this paper we show, that the parameters of viscoelastic inertial support of the string can be varying under the action of the traveling wave pressure. This phenomenon, in turn, changes the amplitude-frequency response of the string vibrations, and in particular, the modulation of the natural frequency of the string can be observed.