Research On The Identification Of Speed-dependent Tool-point FRF During Milling Based On Inverse Stability Solution

In the actual cutting process,the presence of chatter will cause the poor surface finish,reduce the material removal rate,and accelerate tool wear.The Stability Lobe Diagram(SLD)is a powerful tool to avoid chatter,which requires more accurate input,such as the Frequency Response Function(FRF).Therefore,instead of the Tool-point FRF obtained by the experiment or analytical method with the idle machine tool in the traditional research,the Tool-point FRF in the milling process was used.Aiming at the problem that the Inprocess Tool-point FRF can’t be directly measured,this thesis studied the identification of the In-process Tool-point FRF and the Dominant modal parameters,as well as the accuracy and sensitivity of the SLD,which mainly involved the following several aspects:First of all,the impact testing was carried out on the machine tool structure and the tool point,and the tool was the weakness of the machine tool relative to the structure through the response frequency band and response energy,indicating that the Tool-point FRF is more valuable for the study of milling stability.At the same time,according to the SLD obtained under static conditions(Static SLD,SSLD),the experimental plan design was completed,then the chatter experiment method and data acquisition scheme were determined.Secondly,the principle of Analytical Prediction of Stability Lobes in Milling was studied,and an Analytical Chatter Prediction Model based on the Dominant Mode in the Tool-point FRF was proposed.At the same time,the SA identification method for the dominant modal parameters were proposed,which combined the Inverse Stability Solution(ISS)and Simulated Annealing algorithm,and it solved the problem that the In-process Tool-point FRF can’t be directly measured.Finally,the analysis of the accuracy and sensitivity for SLD are completed.The SLD was reconstructed with the In-process Tool-point FRF(Dynamic SLD,DSLD),and compared with the SSLD and chatter experimental data,the accuracy of the DSLD was verified.The Morris screening method was used to perform sensitivity analysis on the input parameters of the SLD,indicating that the SLD is more sensitive to the Dominant Modal parameters in the Tool-point FRF,and the impact results are specifically analyzed.