关键词: 尺寸效应, 微转子, 临界转速, 结构参数

Abstract: At the micrometer scale, the classical mechanical theory can ’ t describe the size effect phenomenon of rotor. Based on the modified couple stress theory, a micro rotor theoretical model considering the size effect of the rotor is established. The governing equations and boundary conditions are derived by using the differential method. The analytical solution of the rotor critical speed is obtained. The influences of the size effect and structural parameters on the rotor critical
speed are analyzed. From the results, it is shown that at the micro scale, the critical speed of the rotor increased significantly. When the material length scale parameter is equal to the radius, the rotor critical speed which obtained by the present model is 1. 5 times larger than the classical result. With the increasing of the radius, when the radius exceeds 15 times the material length scale parameter, the influence of size effect can be ignored. In addition, the rotor critical speed is inversely proportional to the length-diameter ratio of the rotor and the mass of the disc.

Key words: size effect, micro rotor, critical speed, structural parameters