Abstract: A nonlinear rotor system with complex structure in engineering is studied and the finite element analysis software and the multi-body dynamics simulation software are used to establish and analyze the parametric dynamic model of the rigid-flexible rotor system. The dynamic simulation of the rotor system is carried out and the dynamic stress model for reliability analysis is established on the basis of artificial neural network (ANN) technique, stochastic perturbation method, reliability design and reliability-based sensitivity design theory. Thus, an efficient method is proposed to compute the reliability-based sensitivity of the non-linear rotor system with complex structure. The influence degree of the designed parameters on the reliability of rotor system is discussed, and the sensitivity of reliability to the mean value and variance of original random parameters is obtained. On condition that the units of original random parameters are different, the sensitivity is transformed into dimensionless value and each basic random variable is then sequenced by the influence degree of reliability. The proposed method provides theoretical reference for the mechanical product design, thus having realiseic significance and theoretical value.

Key words: Dynamics, Non-linear, Reliability, Rotor system, Sensitivity