NONLINEAR DYNAMICS AND STABILITY OF A MACHINE-TOOL TRAVELING JOINT

In this work, we investigate the nonlinear dynamics and stability of a machine tool traveling joint. The dynamical system considered include s contacting elements of a lathe joint and the cutting process where t he onset of instability is governed by mode coupling. The equilibrium equations of the dynamical system yield a unique fixed point that can change its stability via a Hopf bifurcation. The unstable domain is pr imarily governed by the cutting tool location, the contact stiffness o f the joint and the depth of material to be removed. Self excited vibr ations due to a mode coupling instability evolve around the unstable f ixed point and one or more limit cycles may coexist in the statically unstable domain. Stability and accuracy of the approximate analytical solutions are analyzed by applying Floquet analysis. Perturbation of t he dynamical system with weak periodic excitation results with periodi c and aperiodic solutions.