Computational method of rigid multibody system dynamics considering cylindrical joint clearance

A dynamic model for multi-body system with cylindrical joint clearance was studied. An improved method for detecting potential contact points and the technique for deciding contact and separation were established based on the joint's structural features. The normal contact force was modeled using the continuous approach proposed by Lankarani and Nikravesh, and the tangent friction was calculated using a modified Coulomb's friction law. A unified dynamic equation for multi-body systems was established considering contact and separation scenarios. The numerical analysis of a mechanism with joint clearance indicated that joint clearance has little effect upon other part's motion and causes high contact-impact forces in a short period of time; as time increases, other parts are seriously affected by the joint clearance; however, the axle motions of the contacted parts are influenced by the contact friction. The results of the presented method offered a theoretical reference for dynamic analysis of related and more complex mechanisms.