Modal Analysis of Machine Tool Spindle under Uncertainty

Based on the Timoshenko beam theory, the dynamics model of a spindle system is constructed. The Young’s modulus of the material and the stiffness of bearing are considered as random variables for a Monte Carlo simulation about the spindle system’s first nature frequency. The simulation results shows that the statistical attribute of these parameter introduce variation to the systems dynamics property. The reliability of avoiding the spindle resonance is then calculated.