Characterizing machine tool spatial stiffness and predicting accuracy

As a typical precision machine, the machine tool has complex structure and changeable working conditions, which leads to huge calculation data and low analysis efficiency when using traditional finite element method to obtain stiffness information. General test methods often have discrete values and cannot obtain stiffness information comprehensively and systematically. In this paper, a method for characterizing the stiffness of machine tool processing space based on multi-body system topology is proposed. Based on the matrix condensation theory, a method for constructing the equivalent condensation model of the stiffness of machine tool components is proposed. The stiffness characterization model of the components is established by using the stiffness equivalent condensation method. Based on the multi-body system theory, the stiffness distribution model of machine tool machining space is established, which can quickly and intuitively characterize the machining stiffness information of machine tool. Finally, based on the stiffness distribution model of the machining space of the machine tool, the machining accuracy of the S-shaped test specimen is predicted. Combined with the experimental analysis, the measurement results are consistent with the prediction results. The accuracy, feasibility, and effectiveness of the stiffness distribution model of machine tool machining space are verified.