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Author

Duygu Ertürkmen

Bio: Duygu Ertürkmen is an academic researcher from Çukurova University. The author has contributed to research in topics: Carbon fiber reinforced polymer & Physics. The author has an hindex of 1, co-authored 3 publications receiving 44 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the behavior of carbon fiber reinforced polymer (CFRP) confined plain and steel fiber reinforced concrete columns was examined to determine the effects of sheets on column behavior.

55 citations

Journal ArticleDOI
TL;DR: In this paper , the effect of web opening shapes on displacement, stress values, and free vibration of castellated beams is investigated via the three-dimensional finite element method using ANSYS 22 R1.
Abstract: In recent years, the use of castellated beams has increased significantly across all types of structures. The castellated beam is one of several methods for reducing the weight and cost of steel in construction. In this study, the static and dynamic behavior of castellated beams is investigated via the three-dimensional finite element method. The primary objective of this study is to investigate in detail the effect of web opening shapes on displacement, stress values, and free vibration of castellated beams. The investigation is done using ANSYS 22 R1. In the analysis, 4 different web opening types circle, square, pentagon, and hexagon are used. To generate the models via the finite element method a 10-node tetrahedral type finite element is implemented. This study will employ a linear isotropic homogeneous material with the mechanical properties of steel. As boundary conditions, fixed – fixed, fixed – pinned, and fixed – free are considered. The results for circular, square, pentagon, and hexagon castellated beams made from IPE120, IPE180 and IPE240 profiles are presented in detail. Based on the results, it is seen that the type of web opening has a significant effect on the displacements, von-Mises stresses, maximum shear stress and free vibration values of the considered structures.
Journal ArticleDOI
TL;DR: In this paper , analizlerde daire, kare, beşgen ve altıgen olacak şekilde 4 farklı gövde boşluk tipi kullanılmıştır.
Abstract: Bu çalışmada, eğri eksenli petek kirişlerin statik davranışı, üç boyutlu sonlu elemanlar yöntemi ile araştırılmıştır. Çalışmanın temel amacı, gövde boşluk geometrisinin petek kirişlerin yer değiştirme ve gerilme değerlerine etkisinin detaylı bir şekilde araştırılmasıdır. Analizlerde daire, kare, beşgen ve altıgen olacak şekilde 4 farklı gövde boşluk tipi kullanılmıştır. Sonlu elemanlar yöntemi ile model kurulurken 10 düğümlü tetrahedral tipi sonlu eleman kullanılmıştır. Bu çalışmada kullanılan malzeme lineer izotropik ve homojen olup, çeliğin mekanik özellikleri kullanılmıştır. Sınır koşulları ankastre – ankastre, ankastre – basit ve ankastre – serbest olarak ele alınmıştır. Sonuçlar, IPE220 ve IPE300 profillerinden oluşan daire eksenli petek kirişler için detaylı bir şekilde sunulmuştur. Yapılan tahkiklere göre gövde boşluk tipinin, bu tür yapı elemanlarının yer değiştirme değerleri, von-Mises gerilmeleri ve maksimum asal gerilme değerleri üzerinde önemli ölçüde etkili olduğu görülmektedir.
Journal ArticleDOI
TL;DR: In this article, cylinder-shaped concrete specimens with compressive strengths range between 53.13-74.87 MPa, are wrapped one or two layer with using bi-directional carbon fiber reinforced fabric (CFRP).
Abstract: Lif takviyeli polimer kompozitlerin betonarme yapılarda güçlendirme amaçlı olarak kullanımı son yıllarda oldukça yaygınlaşmıştır. Özellikle yüksek dayanımlı beton kullanılarak üretilen yapı elemanlarının yük etkisi altında sünek davranmasını sağlamak için, dışarıdan lifli polimer malzemeler kullanılarak sarılması alternatif bir güçlendirme yöntemi olarak öne çıkmaktadır. Yüksek çekme dayanımına sahip olan bu malzemeler, kolay uygulanabilmeleri ve hafif olmaları sebebiyle sıklıkla tercih edilmektedir. Bu çalışmada dayanımı 53.13-74.87 MPa arasında değişen silindir şeklindeki beton numuneler (tek veya çift kat) çift yönlü karbon lifli kumaş (CFRP) kullanılarak sarılmıştır. Söz konusu numunelerin eksenel basınç altında test edilmesiyle CFRP sargısının betonun basınç dayanımına ve sünekliğine olan etkileri araştırılmıştır. Ayrıca test edilen numunelere ait elde edilen gerilmedeformasyon ilişkileri literatürde mevcut olan CFRP ile güçlendirilmiş silindir numunelere ait modellerin sonuçları ile kıyaslanmıştır. Sonuç olarak CFRP sargılı numunelerin basınç dayanımlarında ve şekil değiştirme kapasitelerinde önemli artışlar elde edilmiştir. Özellikle çift kat CFRP sargılı durumda elde edilen gerilme-deformasyon değerlerinin, modellerden elde edilen değerler ile oldukça uyumlu olduğu gözlenmiştir. The use of fiber reinforced polymer composites for strengthening in concrete structures has become quite prevalent in recent years. Especially, to provide ductile behavior from the structural elements that produced by using the high strength concrete under the load effects, the externally wrapping of these elements with using the fiber reinforced polymer materials comes into prominence as an alternative method for strengthening. These materials with high tensile strength can often be preferred due to their lightweight and easy to apply. In this study, cylinder-shaped concrete specimens with compressive strengths range between 53.13~74.87 MPa, are wrapped one or two layer with using bi-directional carbon fiber reinforced fabric (CFRP). These wrapped specimens were tested under the axial comprehensive loads and the effects of the CFRP wrapping on concrete strength and ductility was investigated. In addition, stress-strain relations obtained from the tested specimens were compared with the results of existing models for strengthened cylindrical specimen with CFRP in literature. As a result, a significant increase was obtained in the compressive strength and deformation capacity of CFRP wrapped specimens. Especially, it was observed that the stress-strain values obtained from the two layers CFRP wrapped specimens show good agreement with the values obtained from the models.

Cited by
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Journal ArticleDOI
TL;DR: In this paper, the axial compressive behavior of concrete-filled FRP tubes (CFFTs), prepared using different amounts of recycled concrete aggregate (RCA), was investigated under axial compression.

109 citations

Journal ArticleDOI
TL;DR: In this article, the axial compressive behavior of concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs), prepared using either ordinary Portland cement (OPC) concrete (OPCC) or fly ash-based geopolymer concrete (GPC), was investigated under axial compression.
Abstract: This paper presents the results of an experimental study on the axial compressive behavior of concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs), prepared using either ordinary Portland cement (OPC) concrete (OPCC) or fly ash-based geopolymer concrete (GPC). Thirty-six CFFTs were tested under axial compression. The effects of the type of the concrete and FRP tube material, number of FRP layers used in the FRP tube, and specimen cross-sectional shape were studied. The results suggest that the axial stress–strain behavior of CFFTs is affected by the type of concrete, with GPCFFTs developing a similar strength enhancement ratio to but a lower axial strain enhancement ratio than the companion OPCCFFTs. Owing to the higher shrinkage of the OPCC, OPCCFFTs exhibit a plateau at the transition region of their stress–strain curves, which is not seen in GPCFFTs. At a similar confinement ratio, OPCCFFTs confined with different fibers exhibit comparable strength and strain enhancement ratios, whereas slight differences are seen among GPCFFTs manufactured with different fibers. The strength and strain enhancement coefficients of both OPCC- and GPC-FFTs decrease with an increase in the thickness of FRP tube. An accurate model that was originally proposed to predict the ultimate conditions of FRP-confined conventional concrete was modified to enable the application of the model to circular and square GPCFFTs, and it is presented in the final part of the paper.

79 citations

Journal ArticleDOI
TL;DR: In this article, a modified damage-plasticity model for fiber-reinforced polymer (FRP)-confined normal-strength and high-strength concrete (NSC and HSC) is presented.
Abstract: This paper presents a modified damage-plasticity model for fiber-reinforced polymer (FRP)-confined normal-strength and high-strength concrete (NSC and HSC). The proposed model is based on a concrete damage-plasticity model from the literature, which is improved through accurate incorporation of the effects of the confinement level, concrete strength, and nonlinear dilation behavior of FRP-confined concrete. The proposed model uses a new and accurate failure surface and flow rule that were established using a comprehensive and up-to-date experimental test database and it incorporates an analytical rupture strain model for the FRP jacket. Finite-element (FE) models incorporating the proposed damage-plasticity model are developed and validated for concretes having up to 110-MPa compressive strength confined by different types of FRP under a wide range of confining pressures. Comparisons with experimental results show that the model’s predictions of (1) axial stress-axial strain, (2) lateral strain-ax...

60 citations

Journal ArticleDOI
TL;DR: In this paper, the axial compressive behavior of rubberized concrete under active confinement was investigated and the results indicated that the rubber content significantly affects the compressive behaviour of actively confined concrete.

59 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the application of a corner strengthening technique to square and rectangular concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs) and found that increasing the amount of corner strengthening leads to an increase in the confinement effectiveness and results in a more uniform confining pressure distribution along specimen cross-section.

49 citations