Abstract:Taking the allowable displacement as the fuzzy variable and regarding the uncertainties such as loads, material parameters and structural size which affect the displacement of the machine tool spindle as random variables, a reliability analysis model on the stiffness of machine tool spindle under considering of fuzzy failure criterion is presented. The geometric meaning of the fuzzy failure criterion was defined, and the expression of membership function for the fuzzy failure was derived. Based on Gauss-Hermite integration, a numerical algorithm for the fuzzy reliability of the machine tool spindle was developed. Numerical result shows that the proposed method not only can reduce the computational complexity and increase efficiency, but also is consistent with the common sense and more conservative.