A hybrid contact force model of revolute joint with clearance for planar mechanical systems

The contact force model during the contact process of revolute joints with clearance is one of the most important contents. This paper presents a new contact force model of revolute joint with clearance for planar mechanical systems, which is a hybrid model of the Lankarani–Nikravesh model and the improved elastic foundation model. The framework of the Lankarani–Nikravesh model is used with the nonlinear stiffness coefficient derived using the improved elastic foundation model and the damping applied in introducing the ratio of the nonlinear stiffness coefficient of the improved elastic foundation model and contact stiffness of Lankarani–Nikravesh model. Furthermore, the hybrid contact force model is analyzed and compared with Lankarani–Nikravesh model as well as other existing contact models. The tangential contact is represented by using modified Coulomb friction model. And then, the dynamic characteristics of mechanical system with revolute clearance joint are analyzed based on the hybrid contact force model. The correctness and validity of the hybrid contact force model of the revolute joint clearance is verified through the demonstrative application example. Finally, the numerical simulation results show that the presented hybrid contact force model is an effective and new method to predict the dynamic characteristics of planar mechanical systems with clearance in revolute joints.

► We proposed a new contact force model of revolute joint with clearance for planar mechanical system.
► It is a hybrid contact force model with nonlinear stiffness coefficient and modified damping coefficient.
► We presented a modified Coulomb friction model for tangential contact.
► Mechanism with revolute joint clearance is used as numerical example to demonstrate and validate the new contact model.