Nonlinear dynamic analysis of high aspect ratio wings via IHB method

This study investigates the nonlinear dynamics of high aspect ratio wings. A high-dimensional aeroelastic model was developed employing a nonlinear geometric beam model and unsteady aerodynamic loads based on the Wagner function. The time integral term in the aerodynamic model was reformulated in the frequency domain, yielding a more compact system of ODEs compared to existing methods. The improved Incremental Harmonic Balance (IHB) method was then employed to solve the ODE system efficiently. The results were validated using the Runge–Kutta method. The effects of wing eccentricity, stiffness ratio, and aspect ratio on post-flutter limit cycle oscillations were studied. Variations in wing eccentricity and aspect ratio significantly affected flutter speed, oscillation frequency, and complexity, whereas stiffness ratio changes primarily affected oscillation amplitude. This solution method shows potential for more complex aeroelastic systems.