Resumo

VELA MARTINEZ, Luciano et al. Modelación no lineal de las vibraciones auto-inducidas en procesos de maquinado. Ingenier. mecáni. tecnolog. desarroll [online]. 2010, vol.3, n.4, pp.135-142. ISSN 1665-7381.

Self-excited vibrations limit the productivity of machining processes in metallic products. These vibrations originate dynamic instability problems that hinder the rate of removal of material, as well as affect the surface quality of the pieces and accelerate the wear of the cutting tools and the mechanical elements of spindles. This phenomenon presents a highly non-linear chaotic behavior characterized by both subcritical Hopf and doubling period bifurcations. This research deals with self-excited vibrations in machining processes using non-linear dynamic techniques with the aim of predicting with more accuracy the stability conditions in terms of dynamic characteristics and operating conditions of the system. This study is based on a weakly non-linear model with square and cubic terms that represent structural and regenerative nonlinearities. An approximate solution was derived using the multiple-scale method; instability conditions were established due to subcritical Hopf bifurcations. A major contribution of this study is the identification of hysteresis in the conventional stability diagrams, which may be useful to reestablish stability. The analytical model was validated experimentally; the nonlinear behavior of hysteresis was successfully identified by measuring the dynamic response of the system.

Palavras-chave : Chatter; dynamic stability; hysteresis.

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