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Determining Plastic Hinge Length of High Performance RC Beams

Year 2017, Volume: 5 Issue: 2, 39 - 47, 31.05.2017
https://doi.org/10.21541/apjes.297049

Abstract

During
earthquake concrete structures dissipate energy by deforming inelastically. The
plastic deformation localized in a small zone namely the plastic hinge zone is
critical for flexural members as it governs the load carrying and deformation
capacities of the member. Pushover analysis, one method of nonlinear static
analysis, is generally used in the assessment of existing buildings. In
pushover analysis nonlinear hinge properties of each member should be
addressed. The formation of a plastic hinge in structural member depends on
both the structural member properties such as dimension and material
properties. Due to the high non-linearity occurs in plastic hinge zone and
restrictions by the time and cost especially in large tests, very limited
knowledge has been obtained from the laboratory tests up to date. Moreover past
studies showed that none of the existing empirical models is adequate for
prediction of plastic hinge length. This study tries to investigate the problem
numerically using Nonlinear Finite Element Modeling (FEM) approach by employing
software package ABAQUS. To achieve this, a numerical model is generated and
verified with existing experimental studies obtained from the literature, by
comparing load deflection response and rotational capacity of the test
elements. Parametric studies are performed to investigate the plastic hinge
length in terms of material properties concrete and dimensions of the member.
High performance concrete is selected to be as C50, C60 and C80 and dimension
of the beams are determined as deep, intermediate and slender. With the
calibrated FEM model, the extent of concrete crushing zone and rebar yielding
zone are examined to define the plastic hinge length of the member.

References

  • [1] Fenwick, R.C., Thom, C.W., Shear deformation in reinforced concrete beams subjected to inelastic cyclic loading. Research Report No: 279, Department of Civil Engineering, University of Auckland, 1982.
  • [2] Corley, G.W., Rotation capacity of reinforced concrete beams. ASCE J Struct Div. 1966; 121:146-92.
  • [3] Mattock, A.H., Discussion of rotational capacity of reinforced concrete beams by W. D. G. Corley. ASCE J Struct Div. 1967; 519:522-93.
  • [4] Priestley, M.J.N. and Park, R., Strength and ductility of concrete bridge columns under seismic loading. ACI Struct J. 1987; 61:76-84.
  • [5] Panagiotakos, T.B. and Fardis, M.N., Deformations of reinforced concrete members at yielding and ultimate. ACI Struct J. 2001; 135:48-98.
  • [6] Federal Emergency Management Agency. FEMA 356 Prestandart and Commentary for the Seismic Rehabilitation of Buildings. Washington DC, 2000.
  • [7] Park, R. and Paulay, T., Reinforced Concrete Structures. John Wiley & Sons, New York, 1975.
  • [8] Beeby, A.W., Ductility in reinforced concrete: why is it needed and how is it achieved. Structural Engineer. 1997; 311:318-75 (18).
  • [9] American Concrete Institute. Building Code Requirements for Structural Concrete, ACI 318-14, ACI, Detroit, MI, 2014.
  • [10] Wight, J.K., Macgregor JG. Reinforced Concrete Mechanics and Design, 5th Edition, 2012.

Yüksek Dayanımlı Betonla Üretilmiş Kirişlerde Plastik Mafsal Boyunun Belirlenmesi

Year 2017, Volume: 5 Issue: 2, 39 - 47, 31.05.2017
https://doi.org/10.21541/apjes.297049

Abstract

Depremler
sırasında betonarme yapılar elastik olmayan deformasyonlar yaparak yapıya gelen
enerjiyi sönümlerler. Yapılarda bulunan eğilme elemanlarında oluşan plastik
deformasyonlar plastik mafsal bölgesi olarak adlandırılan küçük bir bölgede
oluşur ve bu bölge elemanın yük taşıma ve deformasyon kapasitesi için kritik
öneme sahiptir. Statik itme (Pushover) yöntemi mevcut yapıların
değerlendirilmesinde kullanılan doğrusal olmayan bir analiz yöntemidir. Bu
yöntemde elemanların plastik mafsal özelliklerinin doğru tanımlanması çok
önemlidir. Yapı elemanlarında oluşan plastik mafsal, yapı elemanlarının boyut
ve malzeme özellikleriyle yakından ilgilidir.  Plastik mafsal uzunluğunun belirlenmesinde
günümüze kadar birçok deneysel çalışmalar yapılmış fakat eleman boyutlarının
büyüklüğü, deneysel imkânların yetersizliği ve yapı elemanlarının kompozit
malzeme özellikleri sebebiyle sınırlı bilgi edinilebilmiştir. Bu çalışmada
sonlu elemanlar modeli kurularak ABAQUS yazılımı yardımıyla plastik mafsal boyu
belirlenmeye çalışılmıştır. Literatürden elde edilen deneysel çalışmalar sonlu
elemanlar modeliyle yük-deplasman ve şekil değiştirme kapasiteleri ile
doğrulanmıştır. Plastik mafsal boyunun belirlenmesi için kiriş boyutları kiriş
davranışını değiştirecek şekilde kısa, orta ve narin olarak değiştirilmiş,
kiriş malzemesi de yüksek dayanımlı betona uygun olarak C50, C60 ve C80 olarak
belirlenmiştir. Kirişlerde oluşan yenilme çatlakları ve donatı akma uzunlukları
analiz edilerek her bir kiriş için plastik mafsal boyu belirlenmiştir.

References

  • [1] Fenwick, R.C., Thom, C.W., Shear deformation in reinforced concrete beams subjected to inelastic cyclic loading. Research Report No: 279, Department of Civil Engineering, University of Auckland, 1982.
  • [2] Corley, G.W., Rotation capacity of reinforced concrete beams. ASCE J Struct Div. 1966; 121:146-92.
  • [3] Mattock, A.H., Discussion of rotational capacity of reinforced concrete beams by W. D. G. Corley. ASCE J Struct Div. 1967; 519:522-93.
  • [4] Priestley, M.J.N. and Park, R., Strength and ductility of concrete bridge columns under seismic loading. ACI Struct J. 1987; 61:76-84.
  • [5] Panagiotakos, T.B. and Fardis, M.N., Deformations of reinforced concrete members at yielding and ultimate. ACI Struct J. 2001; 135:48-98.
  • [6] Federal Emergency Management Agency. FEMA 356 Prestandart and Commentary for the Seismic Rehabilitation of Buildings. Washington DC, 2000.
  • [7] Park, R. and Paulay, T., Reinforced Concrete Structures. John Wiley & Sons, New York, 1975.
  • [8] Beeby, A.W., Ductility in reinforced concrete: why is it needed and how is it achieved. Structural Engineer. 1997; 311:318-75 (18).
  • [9] American Concrete Institute. Building Code Requirements for Structural Concrete, ACI 318-14, ACI, Detroit, MI, 2014.
  • [10] Wight, J.K., Macgregor JG. Reinforced Concrete Mechanics and Design, 5th Edition, 2012.
There are 10 citations in total.

Details

Subjects Engineering
Journal Section Articles
Authors

Yusuf Sümer

Publication Date May 31, 2017
Submission Date March 9, 2017
Published in Issue Year 2017 Volume: 5 Issue: 2

Cite

IEEE Y. Sümer, “Determining Plastic Hinge Length of High Performance RC Beams”, APJES, vol. 5, no. 2, pp. 39–47, 2017, doi: 10.21541/apjes.297049.