Weight Optimization of An Aircraft Wing Composite Rıb Using Finite Element Method

Abstract

In present work, weight optimization and weight reduction of composite wing rib design which is one of the wing structural components used in aircraft wing design are studied. As a result of the optimization study on composite wing rib, number of ply and stacking sequence are optimized and optimal weight of the design is obtained. In addition, structural analysis methods are applied on the optimal aircraft structural wing rib design, obtained as a result of the optimization study, in order to examine efficiency of the design in terms of total deflection effects on the wing design and weight reduction. During present study, a hypothetical aircraft wing design is modeled in accordance with the well-known aircraft wing design standards and assumptions. Outer geometry of the wing design is obtained exploiting common wing models of the similar studies in the literature. As the outer geometry of the wing is designed, common structural wing components are placed into model accordingly. Structural analysis and optimization methods are studied on this aircraft wing design. After obtaining overall wing design, a iv finite element model of the design is generated with the presumed aircraft load case and load distribution on the aircraft wing is obtained. Initial thickness of the rib design is optimized by using load distribution obtained as a result of finite element analysis. During optimization study, margin of safety for all predefined regions are investigated and the regions which are evaluated as over safe are determined. The thickness of the regions that are unnecessarily thick and over safe are optimized locally. This optimization method is carried out by using HyperSizer software. By using this optimization method, optimal ply number and stacking sequence are obtained. Over safe designed regions are optimized in terms of weight and thickness. A lighter aircraft wing rib design compared to the initial uniform thickness design is obtained with nearly same stiffness values is reached. This method is important and beneficial especially at the first stage of the design process since it gives an idea about foreseen design can be able to satisfy design criteria such as weight or not. Optimization method described in this study is beneficial to examine total weight of draft aircraft design alternatives at early stages of the design process.