Abstract
The purpose of this investigation is to develop an appropriate model for the friction-induced vibration of a tribological system, where there is at least an order of magnitude difference in the stiffness between the mating subsystems. The significance of this system is that neither system can analytically be considered rigid or aspects of the dynamics that are exhibited experimentally are lost. This leads to the necessity of creating a multi-degree of freedom model, where the multiple degrees of freedom are distributed between the two systems. Experiments have shown that both subsystems contribute to the dynamical response. The modeling starts with the simplest system model, in terms of degrees of freedom, and then progresses to the level required to demonstrate the experimentally observed behavior. An example of such a system is an elastomer sliding against a steel counterface. It has been observed on a variety of dissimilar test devices (linear and rotational) that the subsequent response contains similar dynamical behavior relative to friction-induced vibration. The striking similarities of the dynamic behavior is demonstrated in the friction(time) response, which is subsequently evidenced in the autospectra of friction with an identifiable characteristic form. Specifically, with the exception of scaling in amplitude and frequency, due to system differences, the autospectrum are contained within a characteristic envelope that is determined by both subsystems. While not specifically attempting to model any particular test device or system, representative values of stiffness and estimated friction (velocity) relationships have been incorporated to lend realism to the models.
Quasi-Harmonic Friction-Induced Vibration
