金属切削过程中的分叉与突变现象——兼论切削过程的可控性问题

Bifurcation and Catastrophes in Metal Cutting Processes

通过理论分析，预测出在金属切削过程中存在分叉与突变（ＢｉｆｕｒｃａｔｉｏｎａｎｄＣａｔａｓｔｒｏｐｈｅ）现象，其根源在于切削过程的强烈的非线性，这一发现超出人们对于切削过程的传统认识与理解，可是却得到实验事实的充分验证。研究揭示了切削过程的复杂性及对之进行控制的困难性，从而深化了人们对于切削工艺过程的认识，并要求人们更新切削工艺设计和切屑控制的观念与对策。

Based on a theoretical model and the Principle of Minimum Energy the Bifurcation and Catastrophe in a non free cutting process are theoretically analyzed and experimentally verified. The research reveals that under the same technical condition, a metal cutting process may be in different physical states, e.g., having different chipejection angles, different cutting ratios or different cutting force (i.e., having bifurcation). For this reason, the physical state of a cutting process depends not only on the technical parameters, but also on their variation history, e.g., on the cut in proces.. Furthermore a slight change in technical parameters may result in a sudden jump of the cutting states (i.e., catastrophe emerging). Both the theory and the experiments announce the same behavior above mentioned. This may be the source of complexity of a cutting process as a system with very strong non linearity and the source of the difficulties in its control.