Experimental and theoretical analysis of a power transmission belt

In this paper, the effect of a pulley eccentricity on the vibration of a power transmission belt is experimentally investigated and a theoretical model is developed for validation and identification purposes. This eccentricity gives rise dangerous operating conditions for the system, especially when it excites the frequency range of the belt resonances. As expected, the system shows a hardening nonlinear behavior. Moreover, the fluctuation of the belt tension, due to the pulley eccentricity, gives rise to a parametric instability that can undergo to catastrophic failures of the structure. Experimental observations with quantitative measurements are obtained by means of a laser telemeter. Frequency response curves are drawn when the beam is harmonically excited close to the first and second linear natural frequency. A simple analytical approximation of the system response is obtained by one complex mode approximation. An asymptotic solution justifies the experimental evidence and allows the identification of the main parameters of the equation of motion. The excellent agreement between theoretical and experimental data confirms the consistency of the analytical model and the identification of the parameters.