Modeling and modal analysis of tool holder-spindle assembly on CNC milling machine using FEA

In machine dynamics the modal analysis of tool holder-spindle assembly is carried out to verify the reasonability of spindle speed, recognize the impaction of vibration modes on machining accuracy and optimize the design of spindle. This paper presents modeling and modal analysis of tool holder-spindle assembly utilizing FEA. Bearing supports is simulated by four uniformly distributed translational spring-damper elements and the radial stiffness of bearings is calculated based on Hertz contact theory. The connection at the tool holder-spindle interface is assumed to be the rigid-connection. This study also proposes two numerical methods in the finite element analysis software ANSYS to simulate the rigid-connection. Consequently, the present modeling and analysis approach by use of FEA is feasible for analyzing tool holder-spindle assembly dynamics.