The prediction of chatter vibration is influencedby many known complex phenomena and is uncertain. Wepresent a new effect that can significantly change the sta-bility properties of cutting processes. It is shown that ...The prediction of chatter vibration is influencedby many known complex phenomena and is uncertain. Wepresent a new effect that can significantly change the sta-bility properties of cutting processes. It is shown that themicroscopic environment of chip formation can have alarge effect on its macroscopic properties. In this work, acombined model of the surface regeneration effect and chipformation is used to predict the stability of turning pro-cesses. In a chip segmentation sub-model, the primaryshear zone is described with a corresponding materialmodel along layers together with the thermodynamicbehavior. The surface regeneration is modeled by the time-delayed differential equation. Numerical simulations showthat the time scale of a chip segmentation model is sig-nificantly smaller than the time scale of the turning process;therefore, averaging methods can be used. Chip segmen-tation can decrease the average shear force leading todecreased cutting coefficients because of the non-lineareffects. A proper linearization of the equation of motionleads to an improved description of the cutting coefficients.It is shown that chip segmentation may significantlyincrease the stable domains in the stability charts; fur-thermore, by selecting proper parameters, unbounded sta-bility domains can be reached.展开更多
文摘The prediction of chatter vibration is influencedby many known complex phenomena and is uncertain. Wepresent a new effect that can significantly change the sta-bility properties of cutting processes. It is shown that themicroscopic environment of chip formation can have alarge effect on its macroscopic properties. In this work, acombined model of the surface regeneration effect and chipformation is used to predict the stability of turning pro-cesses. In a chip segmentation sub-model, the primaryshear zone is described with a corresponding materialmodel along layers together with the thermodynamicbehavior. The surface regeneration is modeled by the time-delayed differential equation. Numerical simulations showthat the time scale of a chip segmentation model is sig-nificantly smaller than the time scale of the turning process;therefore, averaging methods can be used. Chip segmen-tation can decrease the average shear force leading todecreased cutting coefficients because of the non-lineareffects. A proper linearization of the equation of motionleads to an improved description of the cutting coefficients.It is shown that chip segmentation may significantlyincrease the stable domains in the stability charts; fur-thermore, by selecting proper parameters, unbounded sta-bility domains can be reached.
