Abstract
A method of measuring contact stiffness and friction damping at interacting plane surfaces of a mechanical system comprised of two sub-structures in dry contact is presented. The method is based on the measurement of displacement ratio of the contacting sub-structures as a function of frequency due to light impulse excitation at a single point on any of the two sub-structures. The theoretical analysis depends on a very simple model of a two-degree-of-freedom system with elastic coupling. The effects of applied normal loads, and contact configuration on the interface parameters are shown. The theoretical and experimental analyses show that the interface properties for the flat-on-flat surfaces of the two contacting sub-structures can be determined from the measured peak amplitude and peak frequency of the microslip in the frequency domain.