Measurement and Computational Methods for Rotational Vibration Analysis in Engine Front End Accessory Drive System

A mathematical model for rotational vibration analysis of a 8 pulley-belt serpentine belt drive system is established.In the model,creeping effect of belt on pulley wrap arc,viscous damping and dry friction of tensioner are considered.Excitation from crankshaft torsional vibration with multi-frequency components is used to analyze the dynamic response of engine frond end accessory drive system(FEAD).Computational method for the steady-state tension in belt spans,natural frequency of a FEAD,rotational response of driven pulley and tensioner arm,dynamic tension of belt span,slip factor between pulley and belt are proposed.Good agreement is obtained between the estimated and tested rotational response of driven pulley and tensioner arm,and tension of each belt span.It is concluded that the dynamic tension of belt span,and slip factor between pulley and belt increase significantly when creeping of belt on pulley is ignored.