Print Email Facebook Twitter Buckling and first-ply failure optimization of stiffened variable angle tow panels Title Buckling and first-ply failure optimization of stiffened variable angle tow panels Author Jeliazkov, M. Sardar Abadi, P.M. Lopes, C.S. Abdalla, M.M. Peeters, D.M.J. Faculty Aerospace Engineering Department Aerospace Structures & Computational Mechanics Date 2015-07-19 Abstract A computationally efficient two-level design methodology is developed for the optimization of stiffened compression loaded panels having variable stiffness panels as their skin. In the first step extensive bay panel optimization is performed using a Rayleigh-Ritz energy method coupled with a specialized Genetic Algorithm. Results in agreement with lamination parameter optima are achieved by employing distinct steered-fiber configurations in different layers. Additionally, a local equivalent laminate robustness constraint is applied, and it is shown to have detrimental effect on the buckling performance of variable stiffness layups. The optimal results obtained are used to characterize the plate buckling response in laminate stiffness space. An approximate analytical model is developed to analyze the buckling-related failure modes of the stiffened panel. Panels are optimized for a variety of configurations and loads. Variable stiffness designs achieve up to 20% weight reduction compared to their straight fiber counterparts, while 5-7% improvements are possible when a local 10% rule is enforced. Varying the fiber orientation is also shown to increase the weight-optimal stiffener spacing. The results indicate that the application of the concept is most promising for lightly loaded configuration, which are driven primarily by buckling, and not material failure. Alternatively, high weight savings are achieved in cases where large stiffener spacing is enforced by non-performance related requirements. Subject bucklingoptimizationstiffened panelsvariable stiffness laminates To reference this document use: http://resolver.tudelft.nl/uuid:86c8c002-7d1e-410f-ab2e-36122120e797 Publisher ICCM Source ICCM 20: 20th International Conference on Composite Materials, Copenhagen, Denmark, 19-24 July 2015 Part of collection Institutional Repository Document type conference paper Rights (c) 2015 The Author(s) Files PDF 321733.pdf 2.56 MB Close viewer /islandora/object/uuid:86c8c002-7d1e-410f-ab2e-36122120e797/datastream/OBJ/view