Dynamic modeling of a micro-endmill based on Timoshenko beam theory

A dynamic model for the over-hanged part of a micro-endmill was proposed comprehensively considering shear deformations and rotary inertia effect due to the nature of the micro-endmill with the theory of Timoshenko beam. The convergence behavior of the built model was analysed, and its correctness was verified with tests. The applicability of the model was proved by comparing the test data with the calculated results using the finite element method and the Euler beam theory. Based on the developed model, the effects of its tool tip diameter, tip section aspect ratio and semi-taper angle on the natural frequencies of the micro-endmill were studied. The proposed model provided a better basis for parametric design and optimization of micro-endmills to improve their dynamic performance.