Natural frequencies and dynamic responses of rotating composite non-uniform beams with an elastically root in hygrothermal environment

Abstract

The vibration characteristics and dynamic responses of a rotating composite non-uniform beam based on Rayleigh beam theory considering the combined influence of hygrothermal environment and elastically restrained root are investigated in this paper. The influence of temperature, humidity and other parameters on the natural frequencies and dynamic responses of the rotating composite non-uniform beam is discussed. Firstly, the Hamilton’s variational principle is employed to establish the governing equation of a rotating composite non-uniform beam. Then, the upper and lower bounds of the fundamental bending frequency are obtained according to the Rayleigh’s and minimum principle. A semi-analytical solution of the governing equation is obtained on the basis of the power series method. Finally, numerical results are performed to analyze the effects of the rotating speed, hub radius, temperature variation, moisture concentration, fiber orientation angle, taper ratio and elastic restrained root on the natural frequencies and dynamic responses.