Optimal Structural Design of a Morphing Aircraft Wing

Open Access
Author:
Bharti, Smita
Graduate Program:
Mechanical Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
March 05, 2007
Committee Members:
  • Mary I Frecker, Committee Chair
  • George A Lesieutre, Committee Chair
  • H J Sommer Iii, Committee Member
  • Farhan Gandhi, Committee Member
Keywords:
  • Aircraft wing morphing
  • topology optimization
  • non-linear Finite Element Analysis
  • Genetic Algorithm
  • Cellular Mechanism
  • Cable Actuation
Abstract:
This work involves the development of design methodologies for a morphing aircraft wing. Morphing aircraft wings face conflicting design requirements of flexibility to accomplish the desired shape change, and stiffness to withstand aerodynamic loads. In this work, two design methodologies are developed. The first involves employing Genetic Algorithm wherein an attempt is made to design optimal wing topologies that meet these requirements. Non-linear Finite Element Analysis is used for function evaluation in order to account for the large deformation requirements of the problem. The solution methodology is applied to solve two wing-morphing problems with very different morphing requirements. Results from the two wing designs are presented. The second design methodology is based on development of an intuitive design to achieve the required wing morphing, followed by performing further analysis and calculation of design parameters. Such a scheme is useful in case of a two-dimensional wing shape change, where the means to achieve the required wing morphing is relatively easy to visualize. However developing an intuitive design for a three-dimensional problem might prove to be more difficult, in which case the scheme employing Genetic Algorithm might be used. Prototype development is presented as a proof of concept for employing cable actuation. The current dissertation presents the results from the two developed design methodologies, along with the design and prototype development of a section of a 10 lb aircraft wing. Details on the implemented Finite Element Algorithm, convergence issues, and minima finding are presented. Possible pitfalls of using a cable actuation mechanism are described, and suggestions for future work are made.