Optimum design of composite stiffened panels with instability considerations

---

Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: ALİ CANKURT

Danışman: SÜHA ORAL

Özet:

In this study, optimum design of stiffened flat panels is investigated with single objective genetic algorithms. The purpose is to have the minimum weight of the stiffeners in stiffened panel with buckling load and some ply configuration constraints. Geometric parameters of the stiffeners and ply angles of both skin and stiffeners are defined as design variables. The ply numbers of both skin and stiffeners are fixed. ANSYS v14.5 is used for the buckling analysis of stiffened panels, and MATLAB is used as the software platform to run the developed genetic algorithm codes. Firstly, the finite element modeling for buckling analyses and optimization method with genetic algorithms are validated with two separate studies found in the literature and good agreement is found between them. Then, a stiffener type having the greatest buckling strength is selected among blade, J, T and hat type stiffeners. Ten randomly defined ply configurations are tried in several sets of analyses for this purpose. Then, the appropriate stiffener type is selected at the end. Finally, optimization studies are conducted with the stiffener type selected. Four optimization studies and their results are presented with the panels having two, three, four and five stiffeners. General conclusions and recommendations are mentioned at the end.