The Calculation of the Acoustical Quantities of Railway Wheels

The objective of the present investigation is to determine the forced vibrations and acoustical characteristics of a wheel disk with a radially varying thickness from the consideration of axisymmetric and nonaxisymmetric bending vibrations. Using Mindlin’s thick plate theory a finite element approximation to describe the natural vibrations of the disk is applied. The forced response of the wheel is derived as the superposition of the natural modes of vibrations using a modal expansion analysis. With the known vibrating velocity on the surface of the wheel disk the sound pressure and the spatial directivity pattern is determined. The sound power is derived from the numerically integrated acoustical intensity in a surrounding sphere. With the sound power and the space-time mean square velocity, the radiation efficiency of a wheel disk which is harmonically excited at the rim is determined for the whole practical important frequency range.