Self-Vibration Studies On Two Degree-of-Freedom Dry-Friction System

The self-excited vibrations induced by dry-friction which are accompanied with stick-slip motions exist broadly in engineering fields. So it is important to study the dynamical systems with the characters of stick-slip in theory or practice.There are many difficulties and complexities in analyzing this kind of system because of the uncontinuity of dry-friction function.Thereby the investigations of this kind of systems are mainly based on the numerical analysis and experiment research,the analytical solution is only rested on the study of single-degree-of-freedom system.But under special condition it is necessary and possible to solve the system by using analytical method. The main work of this paper is investigation of a typical kind of double-mass self-excited system with dry-friction. It reveals the main periodical solution, bifurcation and chaos of slip and stick-slip motions by using the analytical and numerical methods.1. The self-excited vibration system with dry-friction and the model of dry-friction are introduced. A two-degree-of-freedom self-excited mechanical model, double-mass-on-belt with dry friction is given out.2. The pure slip motion of the system is analyzed by using the average method. Based on the numerical analysis results, the pure slip regions of the two masses are determined. The stability of the fixed points is also analyzed.3. The system is investigated using numerical method, to reveal the bifurcation, chaos, multi-period-motion by the time histories and phase portraits, etc. The effects of the system parameters and internal resonance conditon on the complex motions are analyzed.4. At the end of this paper, the main investigation results are summarized.