A finite element model of a 3D dry revolute joint incorporated in a multibody dynamic analysis

In this work a new approach to deal with non-ideal operative aspects of spatial revolute joints by means of a three-dimensional finite element analysis (3D-FEA) is pre- sented. The developed model incorporates the inertia of the joint components and the cor- responding material properties. The fact that actual joint mechanical components present dimensional and geometrical deviations resulting from the assembly process and operative conditions lead to frequent modifications relative to the design conditions that are worth an- alyzing. Such nonconformities include manufacturing tolerances and assembly errors, ther- mal effects, local deformations and clearances that directly affect the behavior and relia- bility of a mechanism, as they are typically at the origin of vibrations, noise and wear. In this work, a comprehensive assessment of the current contact force models implemented in the MultiBody Dynamics (MBD) approach is performed with the aim of understanding its main flaws and weaknesses, validating the need of a new model that is able to evaluate with accuracy the contact forces obtained. Finally, a benchmark problem is presented through a 3D slider–crank mechanism, allowing for the recognition of the differences that exist when the problem is analyzed by means of the MBD and FEM formulations. For this purpose, one of the joints is modeled as non-ideal, with both radial and axial clearances, the ultimate goal of which is to combine both approaches and, thus establish a crucial and pioneering connection to solve the contact problem.The first and second authors express their gratitude to the Portuguese Foundation for Science and Technology through the PhD grants (PD/BD/128385/2017 and PD/BD/114154/2016). This work is supported by FCT with the reference project UID/EEA/04436/2013, COMPETE 2020 with the code POCI-01-0145-FEDER-006941