Applied Optimal Design Techniques Study With The Application Of Advanced Composite Structure

Advanced composite is widely used in designing the structure of aircrafts, for it has some excellent performances such as excellent fatigue, high strength and stiffness ratio,etc. The major characteristic of advanced composite for designing structure is that it combines the mechanical design with the structure design, which gives rise to more design variables and complex influencing factors, so it is more important to optimize advanced composite design.Based on the analysis of advanced composite structure design and its optimal methods, the author in this thesis sophisticatedly discusses the applied optimal design techniques of composite layered panel tail-structure of a developing aircraft in the phase of theoretical layout design by using ANSYS system.Here are the main contents of the paper.The thesis exploits in-deep the systematic tools and APDL commands of the ANSYS for realizing the parameterized finite element modeling and approximate calculations of many design state variables. The modeling work broadens the applicability of numerical finite element model, creates an easy-to-go environment special to theoretical layout design, and also provides a basic technical implementation of the structure optimal design to parameterized structure model.The thesis takes more careful consideration for many applied details in engineering structure optimal technology and introduces the position-parameters of main load-carrying spars into optimal design variables, which greatly improves practicability of optimal technology and working-time efficiency compared with traditional size-parameters optimization. Therefore, to author, it is a beneficial practice in engineering structure optimizing technology.On the basis of theoretical optimal design results, the author redesigns the tail-structure more suitable for engineering application under the general qualitative design rules of composites structure.Through the optimal design work of advanced composite tail-structure, the author summarizes the general methods, processes and skillfulness of the optimal design techniques on the ANSYS software platform. It is a valuable experience useful for exploiting technical functions of large finite elements software.The thesis contents cover seven parts. The first chapter introduces the background and main contents of the research work. The second shows the relative theories of advanced composite and optimization technology. The third is about stiffness matrix theoretical deduction of layered shell finite element. The forth shows the technical features and function modules of ANSYS software. The following two chapters exhibit the main work of the thesis for optimal design of the composite structure and detailed discussion of the optimal results. The last chapter summarizes the theoretical and practical significance and puts forward the prospect of structure optimized design in advanced composite.