Comprehensive aeroservoelastic evaluation of a simplified rectangular wing subjected to parametric control analysis

Resumo

The quality of aircraft flight control systems plays important role in terms of aircraft guidance, but especially
in safety, integrity and stability. Furthermore, such systems enable the response when an external load, such as
gust, reaches the aircraft. The control strategies have become increasingly important in the aeronautical context,
especially in the aeroelastic field when, in addition to inertial, elastic and aerodynamic interaction, control surfaces
can be excited in such a way as to impair aircraft performance or even prevent undesirable aeroelastic phenomena.
With the increase in geometric complexity, availability of lighter materials with high equivalent stiffness, it is also
necessary to update and implement computational tools for aeroservoelastic analysis to ensure not only efficiency
and cost reduction in testing and certification processes but also enable the advent of new technologies. Thus,
this work aims to perform an aeroservoelastic analysis in open and closed loop in a pre-defined geometry related
to a simplified wing in order to compare the control laws usually applied aircraft’s control. The model will be
represented numerically as a cantilever, untapered and unswept wing, with equations of motion obtained from
Lagrange energy methods for various assumed modes of vibrations. The material used in the wing will be linear and
orthotropic. The aerodynamics considered will be equivalent to the non-stationary Theodorsen model, including
Hanckock simplifications. The control laws will be variations of the PID method, under which various parametric
combinations will be involved. The results will be presented in terms of the classic Vgf diagrams, where it is
possible to identify the critical flutter speed. For gust behavior, temporal displacement graphs and spectral density
functions will be studied. Still through ASeS, it will be possible to perform parametric comparisons, highlighting
which factors influence the most in aeroservoelastic stability, making the poper initiative consolidate as an excellent
preliminary aeroelastic design tool.