Nonlinear Vibration Analysis of High-Speed Rotating Pre-Twisted FGM Blades Considering Initial Large Deformations

Rotating pre-twisted blades made of functionally graded materials (FGMs) have broad application prospects in engineering owing to their superior properties. With a high-velocity rotational motion, the blades would exhibit large-amplitude deformations due to the severe centrifugal forces and their vibration behaviors might be affected. This paper presents a nonlinear vibration analysis of rotating pre-twisted FGM blades considering the large-amplitude deformations caused by centrifugal forces. Based on the Carrera unified formulation and 3-D nonlinear elasticity shell theory, a prior large deformation analysis of the FGM blades under centrifugal forces is performed considering the geometrical nonlinear characteristics. The nonlinear vibration analysis of the system about the equilibrium position is then performed taking into consideration the deformed configuration and rotational motion. A systematic comparison of the present results with the 3D FEM solutions is performed to verify the correctness of the present method in determining the large deformation and vibration characteristics of the high-speed rotating pre-twisted FGM blades. The comparative performances of the linear and nonlinear models are assessed in the vibration analysis of the pre-twisted FGM blades with different rotating speeds and material parameters.