Multidisciplinary design and optimization of a composite wing box

Hasan, Muvaffak
In this study an automated multidisciplinary design optimization code is developed for the minimum weight design of a composite wing box. The multidisciplinary static strength, aeroelastic stability, and manufacturing requirements are simultaneously addressed in a global optimization environment through a genetic search algorithm. The static strength requirements include obtaining positive margins of safety for all the structural parts. The modified engineering bending theory together with the coarse finite element model methodology is utilized to determine the stress distribution. The nonlinear effects, stemming from load redistribution in the structure after buckling occurs, are also taken into account. The buckling analysis is based on the Rayleigh-Ritz method and the Gerard method is used for the crippling analysis. The aeroelastic stability requirements include obtaining a flutter/divergence free wing box with a prescribed damping level. The root locus method is used for aeroelastic stability analysis. The unsteady aerodynamic loads in the Laplace domain are obtained from their counterparts in the frequency domain by using Rogers rational function approximations. The outer geometry of the wing is assumed fixed and the design variables included physical properties like thicknesses, cross sectional dimensions, the number of plies and their corresponding orientation angles. The developed code, which utilizes MSC/NASTRAN® as a finite element solver, is used to design a single cell, wing box with internal metallic substructure and composite skins.


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Dababneh, Odeh; Kayran, Altan; Department of Aerospace Engineering (2011)
This thesis gives a comprehensive study on the effect of using different structural idealizations on the design, analysis and optimization of thin walled semi-monocoque wing structures in the preliminary design phase. In the design part, wing structures are designed by employing two different structural idealizations that are typically used in the preliminary design phase. In the structural analysis part, finite element analysis of one of the designed wing configurations is performed using six different one...
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Özkanaktı, Mehmet Harun; Özgen, Serkan; Department of Aerospace Engineering (2015)
This thesis focuses on computational and experimental investigation of three different morphing wing planforms and a baseline wing planform using a commercial CFD software and load cell measurements for the validation of an optimization code developed in a separate study. The wing planforms of interest originate from an optimization tool that minimizes drag for a constant value of lift at a given velocity. The first planform of interest is the planform for optimized drag subject to 14 m/s freestream velocit...
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A two-level optimization procedure for composite wing design subject to strength and buckling constraints is presented. At wing-level design, continuous optimization of ply thicknesses with orientations of 0 degrees, 90 degrees, and +/-45 degrees is performed to minimize weight. At panel level, the number of plies of each orientation (rounded to integers) and inplane loads are specified, and a permutation genetic algorithm is used to optimize the stacking sequence in order to maximize the buckling load. The...
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Accuracy of the functional size is critical in software project management, since functional size is the most prevalent input for effort and cost estimation models. Functional size measurement is performed based on standardized manuals; however, the accuracy of FSM results is still based on the knowledge and cautions of the measurers. In this study we performed a multiple case study to identify the reliability of COSMIC and to observe the frequently encountered errors during functional size measurement. Pro...
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The main objective of this thesis is to write a design tool that will perform the conceptual design phase of an aircraft and achieve the desired specifications of the design. For this purpose, a code is written in MATLAB so that the designer does not have to change or check parameter values when a modification on the mission altitude, cruise conditions, airfoil type, propulsion system units, weight or general geometry of the aircraft. Most of the available design tools are created for large aircraft and not...
Citation Formats
M. Hasan, “Multidisciplinary design and optimization of a composite wing box,” Ph.D. - Doctoral Program, Middle East Technical University, 2003.