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Now showing 1 - 7 of 7
  • Article
    Citation - Scopus: 35
    Elastoplastic Response of a Long Functionally Graded Tube Subjected To Internal Pressure
    (2005) Eraslan,A.N.; Akis,T.
    Plane strain analytical solutions to functionally graded elastic and elastic-plastic pressurized tube problems are obtained in the framework of small deformation theory. The modulus of elasticity of the tube material is assumed to vary radially according to a 2 parametric model in a general parabolic form. The analytical plastic model is based on Tresca's yield criterion, its associated flow rule and ideally plastic material behavior. Exact solutions of field equations for elastic and plastic deformations are obtained. It is shown that the elastoplastic response of the functionally graded pressurized tube is affected notably by the radial variation of modulus of elasticity. It is also shown mathematically that the nonhomogeneous solution presented here reduces to that of a homogeneous one by the appropriate choice of the material parameters. © TÜBİTAK.
  • Article
    Citation - WoS: 46
    Citation - Scopus: 46
    Elastoplastic Analysis of Functionally Graded Spherical Pressure Vessels
    (Elsevier Science Bv, 2009) Akis, Tolga
    Purely elastic, partially plastic and fully plastic stress states of internally pressurized functionally graded spherical pressure vessels are investigated analytically in the framework of small deformation theory. The modulus of elasticity and the uniaxial yield limit of the spherical pressure vessel material are assumed to vary nonlinearly in the radial direction. The plastic model is based on Tresca's yield criterion and ideal plastic material behavior. It is shown that, unlike in the case of a homogeneous spherical pressure vessel, different modes of plasticization may take place due to the radial variation of the functionally grading parameters. (C) 2009 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 2
    Yielding of Radially Pressurized Functionally Graded Long Tubes Based on Von Mises Criterion
    (Gazi Univ, 2015) Akis, Tolga; Eren, Omur
    The elastic behaviour of functionally graded long tubes with axially constrained ends subject to either internal or external pressure is investigated analytically. The modulus of elasticity and the yield limit of the tube material are assumed to vary radially in nonlinear forms. Making use of von Mises yield criterion, the effect of grading parameters on the yielding behavior of the tube is investigated and it is observed that for both pressure cases, the plastic flow may commence at the inner surface, at the outer surface or simultaneously at both surfaces depending on the functionally grading parameters.
  • Article
    Citation - WoS: 51
    Citation - Scopus: 54
    Functionally Graded Hollow Cylinder Under Pressure and Thermal Loading: Effect of Material Parameters on Stress and Temperature Distributions
    (Pergamon-elsevier Science Ltd, 2018) Evci, Celal; Gulgec, Mufit
    This study presents an analytical solution of stresses and displacements in a long functionally graded (FGM) hollow cylinder subjected to uniform heat generation and internal pressure. Thermo-elastic material properties of FGM cylinder continuously vary in radial direction along the thickness with a power function. The temperature distribution is assumed to vary as a function of the radial coordinate and in steady state. Stress formulation approach is employed using the Airy stress function to derive the analytical solution. In the failure analysis of FGM cylinder, Coulomb-Mohr theory is applied for the ceramic phase whereas Tresca yield criterion is used for the metal phase. The stress analysis reveals that stresses in FGM cylinder decrease considerably, compared to the homogenous one, for a particular interval of material parameters. Radial displacement analysis in FGM cylinder supports the results obtained from stress analysis. (C) 2017 Elsevier Ltd. All rights reserved.
  • Review
    Citation - Scopus: 7
    Yielding of long concentric tubes under radial pressure based on von Mises criterion;
    (2005) Akiş,T.; Eraslan,A.N.
    The classical problem of a plain strain tube with free ends, subject to either internal or external pressure is extended to tightly fitted long concentric tubes with axially constrained ends. Making use of von Mises yield criterion, critical values of pressure leading to plastic flow are determined in terms of material properties and tube dimensions.
  • Master Thesis
    Dönen İki Katmanlı Kompozit Tüplerin Akması
    (2009) Dalkılıç, Mehmet; Akış, Tolga
    Bu çalışmanın amacı, dönen iki katmanlı kompozit tüplerin elastik analizi için analitik bir yaklaşım sunmaktır. Gerilme ve yer değiştirmelere ait ifadeler elde edilmiş ve kritik akma koşulları von Mises akma kriteri kullanılarak incelenmiştir. Analitik çözümler ayrıca çeşitli malzeme setleri için uygulanmış ve dönme etkisi altındaki gerilme ve yer değiştirme dağılımları bulunmuştur. Akmanın sistemin iç yüzeyinden, iki tüpün etkileşim yüzeyinden veya özel bir durum olarak, iki tüpün iç yüzeylerinden eş zamanlı başlayabileceği bulunmuştur.
  • Master Thesis
    Basınç Altındaki Çok Katmanlı Kompozit Tüplerin Analitik Olarak İncelenmesi
    (2010) Atlı, Ahmet; Akış, Tolga
    Bu çalışmanın amacı iç ve dış basınç altındaki çok katmanlı kompozit tüplerin gerilme analizi için analitik bir yaklaşım sunmaktır. Tek, iki ve üç katmanlı tüpler için gerilme ve yer değiştirme ifadeleri elde edilmiş ve kritik akma koşulları von Mises ve Tresca akma kriterleri kullanılarak incelenmiştir. Bulunan analitik çözümler çeşitli malzeme setleri için uygulanmış, gerilme ve yer değiştirme dağılımları bulunmuştur. İç veya dış basınç altındaki tek katmanlı tüplerde akmanın iç yüzeyden başladığı bulunmuştur. İki katmanlı tüplerde akma iç veya dış tüplerin iç yüzeyinden veya aynı anda bu iki yerden başlayabilir. Üç katmanlı tüplerde ise malzeme özelliklerine göre farklı akma durumları oluşabilir. Çalışmada bu farklı akma durumlarını oluşturan koşullar etraflıca incelenmiştir.