Design of Nonlinear Impact Dampers Based on Acoustic Behavior

Abstract

In this work, ongoing studies to investigate the vibratory behavior of nonlinear impact dampers will be extended by considering the acoustic properties of these systems in initial design of them. For this reason, mathematical model of the sound radiated from an impact oscillator that incorporates the Hertzian contact will be analyzed. Transient sound generated from the impact of a sphere with a reflecting plane will be obtained theoretically. The calculated results can be verified with previous experimental results. By using the method of images, the acoustical noise radiated from a spherical mass colliding with a wall-floor intersection can be simulated. The theoretical results will be used to predict the sound generated by a single unit impact damper. Furthermore, a nonlinear model will be developed to investigate the effect of mass ratio, coefficient of restitution and gap size on behavior of the impact damper. Finally, damping and acoustic behavior of an impact damper will be shown in a table to find a low noise system, which can strongly suppress the undesired vibrations.