Chatter prediction for milling of flexible pocket-structure

Flexible pocket-structures are widely used in engineering practice, especially in the aerospace industry. This paper presents a dynamic model which is suitable for predicting the chatter vibration during machining the thin bottom of flexible pocket-structures. The model is simplified as a three-degree-of-freedom (DOF) system, in which the cutter is considered to have two orthogonal degrees of freedom in its radial direction while the flexible component is considered to have one degree of freedom in the axial direction of the cutter. Modal analysis is implemented to obtain the system parameters. Thereafter, a semi-discretization method is used to plot the stability lobes. From the stability lobe, it is very easy to predict the appearance of the chatter vibration and thus decide the proper cutting conditions during milling the thin bottom of flexible pocket-structures. At the end of the paper, the developed model is demonstrated by a number of cutting experiments.