Christmas Greeting 2022 - Bells are ringing

A Christmas bell is rung by a harmonic bouncing of a clapper onto the bell surface considering nonlinear contact conditions. The clapper excites the bell due to a prescribed sinusoidal movement which constant frequency lies near the first resonance frequency of the bell at 110 Hz. All deformation and acoustic results are analyzed by Harmonic Balance Method combined with Time History analysis.
The animation on the left side shows the proportion of acoustic sound radiation power for the forth harmonic vibration of all single frequencies in a range between 90 Hz to 130 Hz.
The animation on the right side shows the ringing of the bell in time domain. Therefore all considered harmonics are proportionately superimposed in one period for the selected excitation frequency at 110 Hz.