This report presents the scientific problem of composite structure optimization and their certification. The approach to optimization of a lifting surface (as a wing and empennage) is studied. One of the major elements of structure design is its calculation using the finite element method. It comprises the basic phases input of the initial information on the structure, calculation of the elements stiffness matrices, synthesis of the structure stiffness matrix and solution of the linear algebraic equations system, calculation of the stresses and forces in the elements. The authors have prepared a procedure for optimizing the thicknesses in a structure where the anisotropy angles are allowed to be varied. A computation result is a structure 'equally strong' in respect to multiple loading cases. Comparison shows that a thoughtful variation of anisotropy angles enables a decrease in notably the structural weight. The example is an undercarriage well in a wing, for which two models were employed, one with isotropic elements, and the other with anisotropic elements. The introduction of anisotropy widens the class of reasonable structural concepts and makes it possible to additionally reduce weight and/or raise the stiffness characteristics. After that one can solve the problem of defining the fiber orientation in composite plate with optimal modulus and the optimal angels between moduli.
Composite materials in aircraft structures (design, optimization and certification)
Verbundwerkstoffe in tragenden Flugzeugteilen (Konstruktion, Optimierung und Zertifizierung)
1995
26 Seiten, 19 Bilder, 5 Quellen
Conference paper
English
Composite Materials in Aircraft Structures (Design, Optimization and Certification)
British Library Conference Proceedings | 1995
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Tema Archive | 1987
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