Abstract:During the machining process， the rigidity and natural frequency of the dual-turn-table five-axis machine tool change with the variation of the tool space attitude and the space position of the machine tool components， affecting the machining surface accuracy of the workpiece. In order to accurately predict the dynamic characteristics， this paper establishes one dynamic model and another Kriging prediction model of the different machining space of the dual-turntable five-axis machine tool. According to the measured modal analysis results， the stiffness of the machine tool sliding joint surface is corrected， and 81. The machine tool modalities of two working positions are selected， and the dynamic characteristic variation function of the machine tool is finally selected. Based on the three-dimensional Kriging prediction model， the natural frequency of the system in different processing spaces of the dual-turntable five-axis machine tool is analyzed. Results illustrate that with the change of the swing angle of the pendulum， the variation range of the system natural frequency in the machining space of a dual-turntable five-axis machine tool is between 46.2 Hz and 52.9 Hz. The lowest natural frequency of the system corresponds to the pendulum angle of 00 and 450. The vibration amplitude is the largest； the prediction of the dynamic characteristics of the machining space of the machine tool can provide technical support for machining path planning and tool posture selection.