| Popis: |
During a machining operation, the cutting forces cause a relative movement between the part and the tool that melts the various cutting forces. This phenomenon, called regenerative vibration (self-sustaining), greatly affects the tool life and surface condition of the part. Traditional regenerative stability theory predicts a set of optimally stable spindle speedsat integer fractions of the natural frequency of the most flexible mode of the system. Being able to predict these phenomena therefore makes it easier to choose cutting conditions in order to improve productivity. Over the past twenty years, many theoretical models have been developed for various applications, but there have been very few studies on the particular case of three-axis milling. In this research, it is planned to study the stability of milling operations using a hemispheric tool, using differential equations of delay terms. In this article, a different model is proposed compared to the existing models for peripheral milling and for an aluminum alloy part of type 6061-T6. The model is based on the method of discretization of the lagged terms of the dynamic equation. The work was devoted first to the study of stability by the semi-discretization method, using end mill and secondly to the study of stability by the semi-discretization method, using ball-end mill. |
