Modification of friction for straightforward implementation of friction law

Friction phenomena exist in almost every mechanical device. Due to its complicated nature and influence on the system performance, extensive dynamic simulations are often required in the early system design stage. In this work, a novel approach for eliminating the numerical discontinuity in the classical Coulomb law and its extension is developed. Specifically, the method improves the computation process instead of modifying the Coulomb friction model. The estimated error of this procedure is derived under a simple and idealized model with an externally applied sinusoidal force. Two application examples of a single-body system are used to verify the proposed method, namely, 1-DOF mass-spring system with a moving belt and static ground. Results indicate that the proposed approach reveals the characteristics of the classical Coulomb friction law and its development and eliminates oscillations in the simulated friction force. Furthermore, a 3-DOF multi-body system is simulated to investigate the difference between the LuGre model and the proposed approach.