Abstract
Random response of a material particle pressed on the outer radius of a rotating ring with surface roughness is investigated theoretically and experimentally. The stiffness characteristic of the Hertzian contact between a material particle and a ring is nonlinear, and the theory involves replacing the nonlinear contact spring by an equivalent linear spring with precompression, the stiffness and precompression being determined so as to minimize the error in linearization. In giving the input waviness of the surface of a ring, the power spectral density at each frequency is attenuated by some factor by the fact that the two bodies don't contact at a point but at a finite area, so in the direction of relative movement the height of each harmonic component must be averaged. The response of the contacting bodies is then determined from their point impedance. Acceleration spectra for the material particle have been measured and found to compare very favourably with the calculated spectra.
