A numerical model for vibration analysis of rotating pre-twisted axially functionally graded graphene-reinforced composite beams

Functionally graded graphene-reinforced composites (FG-GPLRC) exhibit unique material properties and vibration characteristics that enable the design of lightweight, high-performance aero-engine blades with superior vibration resistance. In this regard, this study develops a numerical model for rotating pre-twisted axially functionally graded graphene-reinforced composite (AFG-GPLRC) beams, specifically addressing the precise prediction of natural frequencies in composite blades under high-speed rotation conditions. Different from conventional studies focusing on thickness-directional material gradients, the article considers five distribution patterns of graphene content varying along the gradient of the axial direction of the beam. Firstly, the variable cross-section beams are modeled, and the effective material parameters of AFG-GPLRC beams are derived from the modified Halpin-Tsai micromechanical model. The governing equations for axial-torsion-bending-swing coupled vibrations in rotating pre-twisted AFG-GPLRC beams are rigorously formulated through Hamilton's principle and finite element discretization. Model validation is performed through comparative analysis with experimental data from existing literature and self-programmed ANSYS numerical simulations. Systematic parametric analysis demonstrates critical dependencies in beam vibration characteristics. The systematic investigation provides fundamental theoretical support for engineering applications of AFG-GPLRC materials in advanced rotating blade systems.