Session: 03-07: Dynamics and Control of Morphing Wing

Paper Number: 90198

90198 - Dynamics and Stability of Camber Morphing Wing With Time-Varying Stiffness 

Variable camber morphing wing is a promising idea to improve the aircraft performance. Many research works are focused towards the design of camber morphing mechanism and its aerodynamic performance analysis. The aeroelastic analysis of the camber morphing wing through commercial fluid-structure interaction software requires huge computational resources.

1.  Aim:

This research aims to develop the analytical dynamic model and solution methods to study the dynamics and stability of a camber morphing wing with time varying stiffness parameters. The unconventional dynamic response and instability regions induced due to time-varying stiffness are then identified and quantified with these models.

2. Modeling:

Initially, the morphing wing is modelled as binary wing with two degrees of freedom as the bending and torsional modes. The characteristics of morphing structure, which is camber morphing, is modelled by time varying structural stiffness (TVS) for the wing. The amplitude (A) and frequency (F) of the time varying stiffness, due to morphing induced actuation, are taken as key input variables.

Solution methods based on Floquet theory is developed for the stability analysis and solutions for the dynamic response of the camber morphing wing.

3. Numerical stability analysis:

To determine the dynamic stability of the wing during morphing, the Floquet based stability criteria are developed. The analysis is done with bending and torsional modes as uncoupled and coupled cases separately, to study the individual effects on stability.

The instability regions in the parametric space (A and F) are identified, and the nature of the response in those regions is studied.

4. A semi analytical solution

Now, a semi analytical solution for the dynamic response of morphing camber system is developed using a Floquet theory-based harmonic balance method. The unknowns in the assumed response are found out by solving an Eigenvalue problem. The instability regions based on the semi analytical solution are validated with numerically obtained regions. The approximate series solution is found to validate well with the numerical results.

The frequency analysis of the semi analytical solution reveals a pattern that the frequency content of the response follows along the transition zones of stability.

5. Parametric sensitivity analysis:

Sensitivity of the response of the wing to the time varying parameters is carried out for the coupled case numerically.

6. Full paper:

The details of the stability analysis, semi analytical solutions for dynamic response and the effect of other morphing structural parameters will be explained in the full paper.

The camber morphing wing modelling will be further extended to continuous beam model.

Presenting Author: Manoj Prabhakar Indian Institute of Technology Madras