Savaş EVRAN

Eksenel yönde tabakalı fonksiyonel derecelendirilmiş kirişlerin mekanik burkulma davranışı üzerinde tabaka pozisyonlarının etkilerinin incelenmesi

Bu araştırmanın amacı eksenel yönde çoklu tabakalı fonksiyonel derecelendirilmiş kirişlerin mekanik burkulma davranışlarını incelemektir. Sayısal burkulma analizleri ANSYS olarak bilinen sonlu elemanlar yazılımı kullanılarak gerçekleştirilmiştir. Her kiriş konfigürasyonu Zirkonyum (ZrO2) ve Alüminyum (Al) malzemelerinin değişik yüzde hacim fraksiyonları kullanılarak hazırlanmış üç tabaka olarak önerilmiştir. Tabaka seviyeleri ve kirişlerin tabaka pozisyonları Taguchi L9 (33) ortogonal dizi tekniğine göre incelenmiştir. Tabakalar kontrol faktörleri olarak değerlendirildi ve böylece dokuz sayısal analiz tutulu-tutulu sınır şartları altında gerçekleştirildi. Görsel olarak en çok etkilenen tabakaları tespit etmek için eksenel yönde tabakalı olarak fonksiyonel derecelendirilirmiş kirişlerin birinci mod şekilleri gösterildi. Tabakaların optimum seviyelerini elde edebilmek için sinyal-gürültü oran analizi kullanıldı. Sayısal sonuçlar üzerinde önemli etkilere sahip tabakalar ve onların yüzde katkı oranlarını çözmek için Varyans Analizi (ANOVA) uygulandı. En yüksek burkulma yükü Taguchi metodolojisine bağlı elde edilen optimum seviyeli tabakaların değişik pozisyonları kullanılarak karar verildi.

Anahtar Kelimeler:

Fonksiyonel derecelendirilmiş malzemeler, Kiriş, Burkulma, Sonlu elemanlar metodu

Investigation of effects of layer positions on mechanical buckling behavior of axially layered functionally graded beams

The aim of this research is to examine the mechanical buckling behavior of multi-layered functionally graded beams in the axial direction. Numerical buckling analyses were performed using finite element software called ANSYS. Each beam configuration is suggested to be three layers prepared using various percent volume fractions of Zirconia (ZrO2) and Aluminum (Al) materials. The levels of layers and layer positions of the beams were evaluated according to Taguchi’s L9 (33) orthogonal array technique. Layers were determined as control factor and so nine numerical analyses were performed under clamped-clamped boundary conditions. The first mode shapes of the axially layered functionally graded beams were demonstrated in order to detect the most affected layers as visually. Analysis of signal-to-noise ratio was applied to obtain the optimum levels of layers. Analysis of Variance (ANOVA) was employed to solve the layers with significant impacts and their percent contributions on numerical results. The maximum buckling load was determined using various positions of layers with the optimum levels obtained based on Taguchi methodology.

Keywords:

Functionally graded materials, Beam, Buckling, Finite element method,

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