Study On Mechanism And Simulation Of Cutting Chatter Of Machine Tools

Chatter is a complex dynamic problem. In this thesis, the model of turning and millingprocess are investigated. The following works are given:(1) Delay differential equation of the linear single-degree-of-freedom system ofturning chatter is derived on the turning physical model. According to the equations ofmotion, the limit of spindle speed and cutting width are obtained. The results of numericalsimulation and theoretical analysis are discussed.(2) The linear single-degree-of-freedom system of turning chatter is controlled by thesignal of sine, square and saw tooth. According to change the frequency of the waves, theinfluence of the amplitude of the vibration is discussed.(3) Delay differential equation of the nonlinear single-degree-of-freedom system ofturning chatter is derived on the nonlinear factors. Nonlinear dynamic analysis of theequation is discussed. The method of multiple scales is used to solve the delay differentialequations and the bifurcation equation is obtained. According to the bifurcation equation,the influence of parameters on the amplitude of the vibration is investigated. The results ofnumerical simulation and theoretical analysis are compared.(4) Delay differential equations of the nonlinear two-degrees-of freedom system ofmilling chatter are derived on the nonlinear factors of cutting force and machine toolstructure. Nonlinear dynamic analysis of the equation is discussed. The averaging methodwork out the motion delay differential equations and bifurcation equation is obtained.According to the bifurcation equations, the influence of parameters on the amplitude of thevibration is discussed. The results of numerical simulation and theoretical analysis arecompared.