Flapwise vibration analysis of a rotating composite beam under hygrothermal environment

The free vibration characteristics of the rotating composite beam under hygrothermal environment are investigated in this paper. The dynamic properties of the beam affected by temperature, humidity and other factors are discussed. Firstly, the expressions of axial force and bending moment of the rotating composite beam are deduced based on the constitutive relation of single layer material under hygrothermal environment. The influence of temperature and humidity on axial force and bending moment is analyzed. The d’Alembert principle is employed to establish the motion equation in transverse direction of rotating composite beam. The solution to the modal equation is obtained utilizing assumed-modes method. The combined effects of rotating velocity, hub radius, temperature and humidity on the stiffness of structure are researched. Finally, the results of numerical simulation are presented to discuss the influence of temperature, humidity, angular speed, hub radius and fiber orientation angles on the vibration characteristics of rotating composite beam. The results show that the external factors such as rotating velocity and hygrothermal conditions have significant effects on the dynamic characteristics of the rotating composite beam.