Time-varying chatter frequency characteristics in thin-walled workpiece milling with b-spline wavelet on interval finite element method

As the most significant material removal method, milling plays a very important role in the manufacturing industry. However, chatter occurs frequently in milling, which will seriously affect the production efficiency. The accurate prediction of chatter frequency can contribute to chatter monitoring and the design of the controller for chatter mitigation. During thinwalled workpiece milling under chatter, a new phenomenon of time-varying chatter frequency is discovered and explained in this paper. This phenomenon can be explained as follows, with the workpiece material removal, the modal parameters change during thinwalled milling, which can cause the continuous change of chatter frequency. In order to predict the varying modal parameters, this paper provided an efficient tool, the B-spline wavelet on interval finite element method (BSWIFEM), which can possess the material removal problem more accurately and more rapidly. Based on the calculated modal parameters, the time-varying chatter frequency can be obtained with the chatter frequency calculation formulas. To verify the calculated results, a number of milling tests are implemented on thin-walled parts. The experimental results show that the calculated chatter frequency is in good agreement with the measured chatter frequency, which validates the effectiveness of the proposed method.