Finite Element Modeling of Cyclic Behavior of a Reinforced Concrete Chimney Section

Öz

In this study, a numerical model was presented to simulate the experimental behavior obtained for a reinforced concrete chimney section. The purpose of the previous experimental investigation conducted for the chimney section was to evaluate the effect of large openings on the cyclic response in order to reveal the performance of such structures under seismic loads. A detailed finite element model of the chimney section was constructed and all of the reinforcements of the chimney were directly taken into account by line element representations. The volume of the concrete chimney shell was modeled with hexahedral elements. A bi-linear material model was used for the reinforcements. A crucial step in the finite element approach was to employ a constitutive material model that took the multi-axial state of stress and confinement effects in concrete into account. The Winfrith concrete material model of the commercial LS-Dyna structural code was chosen for the shell of the chimney section. Comparisons of the results of the finite element study with the experimental measurements showed a good agreement for the base moment-displacement response and crack formations around the opening regions of the chimney section.

Anahtar Kelimeler

• Reinforced concrete chimneys,Cyclic loading,Finite element model

Betonarme Baca Kesitinin Tekrarlı Yükleme Altındaki Davranışının Sonlu Elemanlar Metodu ile Modellenmesi

Öz

Bu çalışmada, betonarme bir baca kesitinin deneysel davranışına benzer sonuç verebilecek bir sayısal model sunuldu. Daha önce yapılmış olan deneysel çalışmanın amacı, tekrarlı yüklere maruz kalan ve geniş açıklıkları olan baca tipi yapıların deprem yükleri altındaki performanslarını değerlendirebilmekti. Detaylı bir sonlu elemanlar modeli oluşturuldu ve bütün donatılar direkt olarak çubuk elemanlar ile modellendi. Baca kesitinin beton cidarı hacim elemanları ile modellendi. Donatı malzemesi için bilineer bir malzeme modeli kullanıldı. Beton malzemenin çok-eksenli gerilmeler altındaki davranışını ve donatı sargılama etkisini modellemek çalışmada önemli bir adım teşkil etti. Baca kesitinin beton cidarını için ticari bir yapısal çözüm programı olan LS-Dyna’daki Winfrith modeli kullanıldı. Sonlu elemanlar analizinde elde edilen taban momenti-yer değiştirme sonuçları ve betonda oluşan çatlaklar daha önce elde edilen deneysel sonuçlarla karşılaştırıldı.

Anahtar Kelimeler

• Betonarme bacalar,Tekrarlı yükleme,Sonlu elemanlar modeli,Beton malzeme modeli

Kaynakça

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3. 3. Wilson, J.L., 2003. Experimental Study to Investigate the Cyclic Behaviour of Reinforced Concrete Chimney Sections with Openings – Test #5. Research Report, Dept. of Civil & Environmental Engineering, University of Melbourne, Australia.
4. 4. Wilson, J.L., 2009. The Cyclic Behaviour of Reinforced Concrete Sections with and without Openings. Advances in Structural Engineering, 12(3), 411-420.
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9. 10.Broadhouse, B.J., 1995. The Winfrith Concrete Model in LS-DYNA3D. Report No. SPD/D(95)363, Atomic Energy Authority, Winfrith Technology Centre, Dorset, UK.
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