NONLINEAR VIBRATION OF POWER TRANSMISSION BELTS

Non-linear vibration of a prototypical power transmission belt system, which is excited by pulleys having slight eccentricity, is investigat ed through experimental and analytical methods. Laboratory measurement s demonstrate the role of non-linearity in setting the belt's response , particularly in the near-resonance region, and at high running speed s. The belt is coated with a retroreflective medium so as to improve d isplacement and velocity measurements made through non-contact laser i nterferometry. A frequency crossing diagram relates the belt's speed-d ependent excitation and natural frequencies, and is shown to be useful for identifying those speeds at which resonance is expected. Distinct ive jump and hysteresis phenomena in the near-resonant response are ob served experimentally, and are also studied with a model that includes non-linear stretching of the belt. In that regard, a modal perturbati on solution is developed in the context of the asymptotic method of Kr ylov, Bogoliubov, and Mitropolsky for a general, continuous, non-auton omous, gyroscopic system with weakly non-linear stiffness. The solutio n is subsequently specialized to the belt vibration problem at hand. N ear- and exact-resonant response amplitudes are predicted by the pertu rbation method, and they are compared with those obtained by laborator y tests and by direct numerical simulation of the non-linear model. (C ) 1997 Academic Press Limited.