Formation mechanism of chatter surface texture in thin-walled tube turning

The processed surface texture caused by cutting chatter contains abundant processing state information. Here, aiming at turning chatter problems of thin-walled cylindrical workpieces, a combination of theoretical analysis, numerical simulation and test measuring was adopted to study formation mechanism of surface texture under turning chatter. Effects of workpiece dynamic characteristics and machining parameters on surface texture formation were studied. Firstly, the finite element method was used to obtain variation laws of thin-walled tube modes with varying of cutting position in process of a complete cutting. It was shown that natural frequencies of workpiece shell modes have an obviously dropping trend. Furthermore, combined with the cutting surface topography model, the theoretical derivation and explanation showed that the formation of the special vibration texture is related to workpiece size, reduction of natural angular frequency per unit time, and square of revolution number. Finally, cutting tests were conducted to verify the theoretical analysis results. The chatter frequency, workpiece size and cutting parameters in turning process were collected and extracted, and the special vibration texture on thin-walled tube surface was reproduced. The results showed that this study is of significance for prediction and control of surface morphology of thin-walled tube in turning operations. © 2021, Editorial Office of Journal of Vibration and Shock. All right reserved.