Abstract: The dynamics of joints are one of the most important factor affecting the spindle cutting efficiency, processing quality, processing performance in the high-speed spindle system, which is also the foundation of studying the spindle system dynamics. The joints are simplified as the distributing spring, and the finite element modeling is carried out by the finite element method based on the modeling thought of parallel rotor system. After specifying the distribution pattern and stiffness - damper determination of the springs, the finite element modeling process of the spindle system dynamics is proposed, considering the spindle- holder-tool joints. Finally, taking the spindle system of a vertical machining center which installs the BT handle as example, the tip point frequency response function is solved by the finite element modeling using the proposed method. Through the comparison with the actual test, it is found that the proposed modeling approach can better simulate the spindle system dynamics.

Key words: Finite element modeling, High-speed spindle, Parallel rotor system, Spindle-holder-tool joints