Development of an equivalent model of aluminum honeycomb sandwich structures subjected to transverse loads

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2019

Tezin Dili: İngilizce

Öğrenci: OZAN YARDIMCI

Danışman: Ercan Gürses

Özet:

Sandwich structures are commonly employed in aviation because of the weight and strength advantages they provided. This common application has turned the accurate finite element analyses of them into a critical issue. In this thesis, a genetic algorithm-based optimization method is employed for creating accurate two-dimensional layered shell models of the sandwich panels with honeycomb cores. Firstly, the sandwich panels subjected to transverse loads with hexagonal honeycomb cores having different face sheet thicknesses are modeled in their original shapes. Secondly, the layered shell models of the sandwich panels under consideration are created using the equivalent properties. Then, the reaction forces obtained from both models are compared for different face sheet thicknesses. In order to lessen the difference between the reaction forces obtained from different finite element modeling approaches, an optimization tool is employed. The tool optimizes the equivalent core properties used in the layered shell models by eliminating the difference between the reaction forces. Finally, finite element models of the sandwich panels with different geometrical properties, loads and boundary conditions are created to verify the results of the optimization. The results show that the optimization which also considers the effect of the stiffness of the face sheets improves the accuracy of the equivalent models of the sandwich panels under transverse loads.