Beton davranışında mikromekanik modelleme

Betonun malzeme davranışı itibariyle son derece karmaşık bir yapıya sahip olduğu bilinmektedir. Betondan imal edilen yapıların başarılı bir şekilde tasarlanması beton davranışının daha'iyi modellenmesine doğrudan bağlıdır. Kullanılan malzeme modelinin gerçek davranışı temsil etmesi, özellikle yapı elemanlarının göçme yükleri hesaplanırken oldukça önemlidir. Bu amaçla geliştirilen birçok model malzeme mikromekaniğine dayanmaktadır. Bu çalışmada, betonun mekanik davranışı, mikromekanik yaklaşımla sayısal olarak modellenmiş ve sunulan modelin geçerliliği literatürde mevcut bir takım deneysel verilerle karşılaştırılarak araştırılmıştır.

Micromechanical modelling in concrete behavior

It is known that constitutive behaviour of concrete has a complex structure. Project performance of concrete structures depends directly on the modelling of their behaviour. Especially when the collapse loads of structural members are of interest, representing of actual behaviour by material models is quite important. For these purposes, many of developed constitutive models are based on material micromechanics. In this study, mechanical behaviour of concrete was modelled numerically by means of a micromechanical approach and the validity of presented model was investigated by using suitable experimental data in literature.

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1.Bazant,Z.P., "Microplane Model for Strain controlled inelastic behaviour", Chapter 3 in Mechanics of Engineering Materials (Proc., Conf. held at U. of Arizona, Tucson, Jan. 1984), C.S. Desai ve R. H.Gallagher, eds. , J.Wiley, London, 45-59, 1984.

2.Taylor,G.I., "Plastic strain in metals", Journal of Inst. Metals, 62, 307-324, 1938.

3.Batdorf, S.B. ve Budianski,B. "A math, theory of plasticity based on the concept of slip", Tech. Note No: 1871, Nat. Advis. Comm. for Aeronautics, Washington D.C., 1949.

4.Bazant,Z.P., Prat, P.C, "Microplane Model for brittle plastic material: I.Theory",Journal of Engineering Mechanics, ASCE 114, 1672-1688, 1988a.

5.Bazant,Z.P. ve Oh,B.H., "Microplane Model for progressive fracture of concrete and rock", Journal of Engineering Mechanics, ASCE 111, 559-582, 1985.

6.Bazant,Z.P. ve Oh,B.H., "Efficient Numerical Integration on the surface of a sphere", Zeitschrift fur angewandte Mathematik und Mechanik (ZAMM, Berlin), 66, (1) 37-49, 1986.

7.Bazant,Z.P. ve Planas,J., "Fracture and Size Effect in Concrete and Other Quasibrittle Materials" CRCPress, Boca Raton, Florida, (ISBN: 084938284X), 1997.

8.Carol,I, Jirasek,M. ve Bazant,Z.P., "New thermodynamic approach to microplane model. Part I: Free Energy and consistent microplane stresses ", Report, Norhwestern University; 1999.

9.Bazant,Z.P. ve Zi,G., "Microplane Constitutive Model for Porous Isotropic Rocks", Int. J. for Num. and Analytical Meth. in Geomechanics, 2002.

10.Bazant,Z.P., Xiang,Y. ve Prat,P.C., "Microplane Model for Concrete. I. Stress-Strain boundaries and finite strain", Journal of Engg. Mech., ASCE 122(3), 245-254,1996a.

11.Stroud,A.H., "Approximate Calculation of Multiple Integrals", Prentice-Hall, Englewood Cliffs, NJ, 1971 (ASIN: 0130438936).

12.Bazant,Z.P., Caner,F.C., Adley,M.D., Akers,S.A.,"Microplane model M4 for concrete I: Formulation with work-conjugate deviatoric stress" J. of Eng. Mechanics, ASCE, 126(9): 944-953, 2000.

13.Örnek,M., Caner,F.C. ve Deliktaş,B., "Modelling Studies to Simulate Mechanical Behavior Of Concrete ", 3rd FAE, International Symposium, TRNC, 2004.

14.Caner,F.C. ve Bazant,Z.P., "Microplane model M4 for concrete, II. Algorithm and Calibration", ASCE Journal of Engineering Mechanics, Vol.126, No.9, pp. 954- 961, 2000.

15.Örnek,M., "Beton Mekanik Davranışının Mikromekanik Yaklaşımla Sayısal Olarak Modellenmesi", Yüksek Lisans Tezi, Mustafa Kemal Üniversitesi, Fen Bilimleri Enstitüsü, Antakya, Hatay, 2004.

16.Petersson,P.E. "Crack growth and development of fracture zones in plain concrete and similar materials'", Report No. TVBM 1006, Lund Inst. of Technology,Lund, Sweden, 1981.

17.Bresler,B., ve Pister,K.S. "Strength of concrete under combined stresses'", J. Am.Concr. Inst, 551(9), 321-345, 1958.