基于应变能分布的高速转子系统动力特性设计

Aiming at the problems of numerous iterative parameters, unclear influence rules, and cumbersome iterative calculation process in the optimization design of dynamic characteristics of high-speed rotor system, a dynamic model of high-speed rotor system is established considering key structural features such as skew of principal axes of inertia and local stiffness between the disk and shaft, the intrinsic relationship between rotor strain energy distribution under first bending mode and the critical speed as well as bearing dynamic load is revealed based on the Rayleigh method and Euler beam theory, and the variation law of the critical speeds and load characteristics of the rotor with the strain energy proportion of elastic structural elements under high operating speed is obtained. The results of the numerical example show that strain energy distribution of the high-speed rotor under first bending mode has a high correlation with its critical speed as well as bearing dynamic load, and is sensitive to key structural design parameters such as local stiffness between the disk and shaft. Accordingly, a new idea of taking the strain energy distribution as optimal design goal is proposed, and a high-speed rotor dynamic characteristic design method based on strain energy distribution is developed. Compared with traditional harmonic response analysis method, this method reduces total iterative design time by 98%, and when the critical speed and bearing dynamic load are controlled by strain energy distribution, the control relative error does not exceed 3%, which effectively avoids large amount of calculation and time-consuming in the traditional iterative design process of high-speed rotor, showing engineering practical value in the high-speed rotor dynamics design of aircraft gas turbine engines.