Spatial revolute joints with clearances for dynamic analysis of multi-body systems

This paper presents a new technique for assessing the influence that clearance of spatial joints has on the kinematics and dynamics of multi-body systems. The technique is developed for the revolute joint in which the basic elements are the journal and bearing. Under certain working conditions, these two mechanical elements collide with each other being the contact treated as coupled forces. The forces between each pair of contacting bodies are equal and opposite, and the magnitude and direction are calculated based on the positions and velocities of the bodies, as well as on the geometry of the joint. A continuous contact force model is used to evaluate the contact-impact force. The proposed methodology is developed in the framework of the multi-body systems formulation; therefore, the forces developed during the contact between the joint elements are introduced into the systems' equations of motion as external forces. A double pendulum is used as a numerical example to show the application of the proposed methodology, being the efficiency of the developed methodologies discussed in the process of the results obtained.