Sources of nonlinearities, chatter generation and suppression in metal cutting

The mechanics of chip formation has been revisited in order to understand f unctional relationships between the process and the technological parameter s. This has led to the necessity of considering the chip-formation process as highly nonlinear, with complex interrelations between its dynamics and t hermodynamics. In this paper a critical review of the state of the art of m odelling and the experimental investigations is outlined with a view to how the nonlinear dynamics perception can help to capture the major phenomena causing instabilities (chatter) in machining operations. The paper is concl uded with a case study, where stability of a milling process is investigate d in detail, using an analytical model which results in an explicit relatio n for the stability limit. The model is very practical for the generation o f the stability lobe diagrams, which is time consuming when using numerical methods. The extension of the model to the stability analysis of variable pitch cutting tools is also given. The application and verification of the method are demonstrated by several examples.