A simplified model of the base-excited coulomb friction oscillator with contact compliance and inertia

This work investigates a base-excited Coulomb oscillator with contact compliance and inertia. The full-order system is a two degree-of-freedom (DOF) problem. The study first shows that two existing approximate models, including the rigid-contact model (RCM) and the compliant-contact model (CCM) cannot closely capture the dynamical characteristics of the global pure-sliding responses of the full-order system (FOS). To complement for this, this study proposes a new approximate model denoted as the reduced-order system (ROS), which is especially suitable for studying the contact dynamics subjected to the global pure-sliding motion. Numerical results show that the ROS not only has the merit of simplicity can also reliably depict the global pure-sliding features of the FOS. Furthermore, relevant stick-slip phenomena associated with the ROS (the transformed problem) are revealed and illustrated in time-domain and phase-space trajectories.