Investigation of the small-scale effects on the three-dimensional flexural vibration characteristics of a basic model for micro-engines

摘要: The coupled three-dimensional flexural vibrations of a micro-rotating shaft–disk system, as basic model for micro-engines, are investigated in this paper by considering small-scale effects utilizing the modified couple stress theory. Governing equations motion derived use Hamilton’s principle. Then, implementing Galerkin approach, an infinite set ordinary differential is obtained system. With truncated two-term equations, expressions first two natural frequencies written, and corresponding modes, maximum rotational speed up to which system will be stable analytically determined. Parametric studies on results different responses illustrate that length-scale value has significant effect shaft threshold instability