A driveline system with a double Cardan joint may be subject to severe vibration due to fluctuations in angular speed determined by the degree of angular misalignment and the phasing of the joint yokes. The inner yokes of the two joints are usually in the same plane or in phase. In this study, the potential of an out-of-phase position displaced by a phase angle to attenuate torsional vibration of the driveline is investigated. The governing equations describing the torsional dynamics of the system are derived. The torsional vibration is indicated by a maximum and minimum value of the steady-state twist calculated over a range of input rotational speeds. When attenuating the vibration, the phase angle is set equal to the maximum twist that occurs during the in-phase position. Relative attenuation is used to study the percentage of attenuation of the twist due to phase angle effects. The effectiveness is investigated for different levels of angular misalignment. For the system considered, the results showed that the phase angle can attenuate the torsional vibration by more than 10 percent for angular misalignment greater than 20 degrees.
