Finite Element Study of Belt-Drive Frictional Contact under Harmonic Excitation

Belt-drives that are driven by internal combustion engines, such as automotive accessory drives, are subjected to high-frequency periodic excitation due to engine combustion events. This excitation is propagated from the engine through the crank pulley and the belt to the accessory pulleys and may cause unwanted system behavior, to include 1) excessive creep or gross slip of the belt on one or more pulleys, 2) large belt-span transverse vibrations, 3) and/or large belt-span tension variations. In turn, the excitation may be responsible for premature degradation and failure of the belt or other components of the belt-drive.

In this paper, an explicit time integration finite element code is used to study the effect of harmonic excitation on the belt-drive operation of a prototypical two-pulley belt-drive. In particular, the study documents the effect of excitation frequency and magnitude on: the belt tension and friction forces along the contact arc, the extent of belt creep or gross slip on the pulleys, the angular velocity of the driven pulley, and the belt-span tension fluctuations. A previously developed closed-form approximate analytical solution that is valid over a limited range of excitation frequencies and amplitudes is used to validate the finite element solution.