Study on vibration suppression performance of a flexible fixture for a thin-walled casing

Abstract

Because of its poor rigidity, a thin-walled casing can easily cause chatter during the cutting process, which seriously affects the efficient processing of the casing, so some measures are needed to suppress the flutter. In this paper, a dynamic model of flexible fixtures for thin-walled casings is presented. This model differs from the analysis of casings with rigid fixtures. A new flexible fixture has been designed based on the principle of multiple dynamic vibration absorbers. A hybrid dynamic model of the lumped mass method and the finite element method for thin-walled casings and flexible fixtures has been developed, and the effect of flexible fixtures on the vibration suppression of thin-walled casings is analyzed. To verify the model, a typical thin-walled casing is taken as an example, and the accuracy of the dynamic model is verified by the comparison between the modal test results and the simulation results. The simulation and experimental results show that the model can effectively reflect the dynamic response of thin-walled casings under the flexible fixture. With a flexible fixture, the corresponding amplitude of the frequency response of the casing is reduced, and the frequency is shifted to the right. Through cutting experiments, it is found that the low-order vibration amplitude of the system is reduced by nearly 20 times and the coupling vibration amplitude of the cutter and the workpiece is reduced by nearly 5 times with a flexible fixture. Finally, it is also noted that flexible fixtures are an effective measure to suppress casing flutter.