Vibration of airfoil panel under aerodynamic load: Experimental verification and theoretical research

The wing is a critical aerodynamic component of aircraft, necessitating in-depth investigation into its dynamic behavior under supersonic flow. However, a unified analytical framework for effectively solving its resonant response, flutter, and limit-cycle oscillations (LCOs) remains lacking. To address this research gap, this study simplifies the outer wing model of Lockheed Martin unmanned aerial vehicle to an airfoil panel model and systematically investigates the nonlinear vibrations of the graphene-reinforced porous composite (G-RPMC) sandwich airfoil panel under combined thermal environment, aerodynamic loads and external transverse excitations. The sandwich panel rests on a Winkler-Pasternak elastic foundation (W-PEF), simulating insulation or damping tape, while its connection to the fuselage is modeled via elastic springs to represent arbitrary support boundaries. The effective material properties of the G-RPMC are derived based on the Halpin-Tsai micromechanical model. The aerodynamic load model of the airfoil panel is obtained by the first-order piston theory. The geometric modeling of the airfoil panel is achieved via a four-node coordinate transformation scheme in conjunction with the chain rule. The governing equations of motion are subsequently formulated as a set of nonlinear ordinary differential equations with multiple degrees of freedom using Lagrange’s equations. The accuracy of the proposed methodology is rigorously verified by comparing the present theoretical results with both finite element simulations conducted in ANSYS and experimental modal tests, showing excellent agreement. Additional validation is provided through linear frequency-sweeping experiments, which further corroborate the reliability of the model. These results unequivocally demonstrate that graphene reinforcement not only improves stiffness but also actively mitigates nonlinear vibration phenomena, offering a novel and validated framework for designing advanced composite airfoil panels with superior dynamic performance in supersonic environments.