Design of nonlinear impact dampers based on acoustic and damping behavior

In the present study, mathematical model of the sound radiated from an impact oscillator that incorporates the Hertzian contact is analyzed. Transient sound generated from the contact of a sphere with a reflecting plane is obtained theoretically and it is compared with the previous experimental results. The acoustic noise radiated from a spherical mass colliding with a wall–floor intersection is obtained using the method of images. This method is used to predict the acoustic noise generated by a single unit impact damper. A nonlinear model is developed to investigate the effect of mass ratio, coefficient of restitution and gap size on behavior of the single unit impact damper. Finally, damping and acoustic behavior of the impact damper are illustrated in a user-oriented diagram to find a low noise system, which can strongly suppress the undesired vibrations.

► Transient sound generated from an impact damper is theoretically obtained.
► A nonlinear model describes vibratory behavior of the impact damper.
► We investigate acoustic behavior of the impact dampers.
► A low noise impact damper is designed.
► This impact damper can strongly suppress undesired vibration.