Camshaft torsional vibration is examined when a nonlinear stiffness characteristic of the timing belt is included. First the camshaft system was modeled with 16 lumped masses and the timing belt nonlinear stiffness is measured experimently. The reliability of the constructed model was checked by comparing the measured and calculated natural frequencies. As examing the camshaft torsion vibration, it was found that the torsional stiffness of camshaft is far greater than that of the timing belt and concluded that the camshaft flexibility can be ignored when analysing the camshaft torsional motion. Then a 1dof is constructed and the camshaft torsional motion is simulated with varing system parameters such as the camshaft intertia, timing belt stiffness and the flutuating torque due to valve train motion.
Those simulation results can be a good guideline to understand the camshaft torsional motion expecially due to a nonlinear stiffness of the timing belt.
