Nichkawde, Chetan (2003-05). Nonlinear aeroelastic analysis of high aspect-ratio wings using the method of numerical continuation. Master's Thesis. Thesis uri icon


  • This research explores the impact of kinematic structural nonlinearities on the
    dynamics of a highly deformable cantilevered wing. Two different theoretical formulations
    are presented and analysed for nonlinear behavior. The first formulation, which
    is more conventional, assumes zero equilibrias and structural nonlinearities occur as
    terms up to third order in the Taylor series expansion of structural nonlinearities.
    In the second approach, no prior assumption about equilibria states of the wing is
    made. Kinematic nonlinearities due to curvature and inertia were retained in their
    exact form. Thus, the former becomes a special case of the latter. This nonlinear formulation
    permits the analysis of dynamics about nonzero trims. Nonzero trim states
    are computed as a system parameter is varied using a continuation software tool. The
    stability characteristics of these trim states are also ascertained. Various bifurcation
    points of the system are determined. Limit-cycle oscillations are also investigated for
    and are characterized in terms of amplitude of vibration. The research in particular
    examines the impact of in-plane degree of freedom on the stability of nonzero trim
    states. The effect of variation of system parameters such as stiffness ratio, aspect
    ratio and root angle of attack is also studied. The method of direct eigenanalysis of
    nonzero equilibria is novel and new for an aeroelastic system.

publication date

  • May 2003
  • May 2003