Paper
description
Transcript of Paper
Materials and Design 31 (2010) 278–286
Contents lists available at ScienceDirect
Materials and Design
journal homepage: www.elsevier .com/locate /matdes
Plasticity models for concrete material based on different criteria includingBresler–Pister
Tayfun Dede *, Yusuf AyvazDepartment of Civil Engineering, Karadeniz Technical University, 61080 Trabzon, Turkey
a r t i c l e i n f o a b s t r a c t
Article history:Received 25 March 2009Accepted 12 June 2009Available online 17 June 2009
Keywords:Failure analysisConcretePlastic behaviorBresler–Pister criterion
0261-3069/$ - see front matter � 2009 Elsevier Ltd. Adoi:10.1016/j.matdes.2009.06.018
* Corresponding author. Tel.: +90 462 3772638; faxE-mail address: [email protected] (T. Dede).
The purpose of this study is to investigate nonlinear behavior of reinforced concrete (RC) structures withthe plasticity modeling. For this aim, a nonlinear finite element analysis program is coded in MATLAB.This program contains several yield criteria and stress–strain relationship for compression and tensionbehavior of concrete. In this paper, the well-known criteria, Drucker–Prager, von Mises, and Mohr Cou-lomb, and a new criterion-Bresler–Pister are taken into account. The elastic–perfectly plastic and Saenzstress–strain relationships in compression and tension stiffening in tension behavior of concrete are usedwith four different yield criteria mentioned above. The proposed models are in good agreement with theexperimental and analytical results taken from the literature. It is concluded that the coded program, theproposed models, and Bresler–Pister criterion can be effectively used in nonlinear analysis of reinforcedconcrete beams.
� 2009 Elsevier Ltd. All rights reserved.
1. Introduction
Considerable constitutive models have been proposed to definenonlinear behavior and stress–strain relationship of reinforcedconcrete (RC) material. These models can be classified into ortho-tropic models, nonlinear elastic models, plasticity models, endo-chronic models, fracture mechanics models and micromodels [1].Using these models, several studies have been made in the fieldof nonlinear analysis of RC structure to predict the behavior ofreinforced concrete structures more reliable. Arslan [2] investi-gated the sensitive of the Drucker–Prager modeling parametersand the use of it in plasticity theory for shear design of RC beams.Park and Klingner [3] presented a nonlinear analysis study of RCmembers by using plasticity multiple failure criteria. Wang andHsu [4] applied the nonlinear finite element analysis to varioustypes of RC structures using a new set of constitutive models. Bra-tina et al. [5] presented a study on materially and geometricallynonlinear analysis of RC planar frames by dealing with the fiber-based constitutive equations of concrete and steel. Zhao et al. [6]studied the load-deflection and failure characteristics of deep RCcoupling beams. Pankaj and Lin [7] used two similar continuumplasticity material models to examine the influence of the materialmodeling on the seismic response of RC frame structures. Belmou-den and Lestuzzi [8] investigated post peak modeling and nonlin-ear performance of RC structural walls. Bischoff [9,10],
ll rights reserved.
: +90 462 3772606.
Stramandinoli and Rovere [11] and Dede and Ayvaz [12] studiedon RC structures by considering tension stiffening effect.
Among the models given above, plasticity models need a yieldfunction, a hardening rule, a flow rule and a stress–strain relation-ship to construct the plastic material matrix for the plastic behav-ior of concrete. A review of the literature indicates that there arenot any studies based on the Bresler–Pister criterion for plasticbehavior of concrete. This yield function can be found in the booksconcerning with the plasticity theory. But, its plasticity materialmatrix or any application of this function to the RC structures isnot found.
In this paper, derivation of plastic material matrix based onBresler–Pister yield function and two applications of this functionto the RC beams are presented. For this aim, a nonlinear finite ele-ment analysis program is coded in MATLAB. This program containsseveral yield criteria and stress–strain relationship for compressiveand tensile behavior of concrete. In the nonlinear analysis, thewell-known criteria, Drucker–Prager, von Mises, and Mohr Cou-lomb and as a new criterion, Bresler–Pister, are taken into account.The elastic–perfectly plastic and Saenz stress–strain relationship incompressive and tension stiffening in tensile behavior of concreteare used with four different yield criteria mentioned above.
2. Yield criteria for concrete
The concrete is assumed to be elastic until it reaches the yieldlimit. Beyond yielding, plastic deformations take place. So, residualplastic deformations remain after removing the loading. A consid-erable amount of formulations have been proposed for concrete as
Nomenclature
f 0c uniaxial compressive cylinder strengthf 0t uniaxial tensile strengthh angle of similaritys effective von Mises stress/ internal friction angled kronecker deltaa, k material parametersecr cracking strain of concretercr cracking stress of concreterf, ef control point coordinates on stress–strain curveroct octahedral normal stresssoct octahedral shear stressep concrete strain corresponding to rp
rp peak concrete compressive stressqx reinforcement ratio in global direction of the X axisqy reinforcement ratio in global direction of the Y axisc cohesion
D elastic material-stiffness tensorDc material matrix of concreteDep elastic–plastic material-stiffness tensorDp plastic material-stiffness tensorDs material matrix of equivalent reinforcing bar elementsE Young’s modulusf yield functionHp plastic hardening modulusI1 first invariant of stress tensorJ2 second invariant of stress deviator tensorJ3 third invariant of deviatoric stress tensorK initial tangent moduluss deviatoric stresse strainee elastic strainep plastic strainr stress
Table 1Test data for Bresler–Pister Criterion.
Test roct=f 0c soct=f 0c
r1 ¼ f 0t13
�f 0tffiffi2p
3�f 0t
r3 ¼ �f 0c � 13
ffiffi2p
3
r2 ¼ r3 ¼ �f 0bc � 23
�f 0bc
ffiffi2p
3�f 0bc
T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286 279
a yield function such as Drucker–Prager, von Mises, Mohr Cou-lomb, Tresca, Rankine, William Warnke, Ottosen, Hsieh Ting Chen,and Bresler–Pister [13]. The well-known yield function for Druc-ker–Prager, von Mises, and Mohr Coulomb are given by the follow-ing equations, respectively [14].
f ¼ aI1 þffiffiffiffiJ2
p� k ð1Þ
f ¼ffiffiffiffiJ2
p� k ð2Þ
f ¼ I1 sin /þ 12
3ð1� sin /Þ sin hþffiffiffi3pð3þ sin /Þ cos h
h i ffiffiffiffiJ2
p� 3c cos / ð3Þ
cosð3hÞ ¼ 3ffiffiffi3p
2J3
J3=22
: ð4Þ
where f is yield function, a and k are the material parameters, c iscohesion, / is internal friction angle, I1 is the first invariant of stresstensor, J2 is the second invariant of deviator stress tensor, J3 is thethird invariant of deviator stress tensor, and h is angle of similarity.
The Bresler–Pister criterion is the extension of Drucker–Pragercriteria. This yield function in terms of octahedral stresses is givenby
soct
f 0c¼ a� b
roct
f 0c
� �þ c
roct
f 0c
� �2
: ð5Þ
where a, b, and c are the material parameters of this yield function.These parameters can be established by using available experimen-tal test data given in Table 1 [14]. In this table, �f 0t and �f 0bc are the nor-malized strengths, f 0t is uniaxial tensile strength, f 0c is uniaxialcompressive cylinder strength, f 0bc is equal biaxial compressivestrength, roct is octahedral normal stress and soct is octahedral shearstress.
The octahedral normal and shear stresses are given by the fol-lowing equations, respectively.
soct ¼ffiffiffiffiffiffiffiffi23
J2
r
roct ¼I1
3
ð6Þ
The normalized strengths are given by the following equations.
�f 0t ¼f 0tf 0c; �f 0bc ¼
f 0bc
f 0c: ð7Þ
When these experimental test data are substituted into Eq. (5), theparameters a, b and c can be obtained by solving a system of threelinear equations given below.
a ¼ffiffiffi2p
3�f 0t
�f 0bcð8�f 0bc þ �f 0t � 3Þ=D
b ¼ffiffiffi2pð4�f 02bc � �f 0bc � �f 0bc
�f 0t þ �f 0tÞð1� �f 0tÞ=Dc ¼ 3
ffiffiffi2pð3�f 0t
�f 0bc � �f 0bc � 2�f 0tÞ=D
ð8Þ
where
D ¼ ð2�f 0bc � 1Þð2�f 0bc þ �f 0tÞð1þ �f 0tÞ ð9Þ
Substituting Eq. (6) into Eq. (5) and rewriting Eq. (5), the Bresler–Pister yield function in terms of stress invariant can be obtained,and it is given as
f ¼ c9f 02c
� �I21 �
b3f 0c
� �I1 �
ffiffiffiffiJ2
pffiffiffi3p
f 0c
! ffiffiffiffiJ2
p� a: ð10Þ
3. Plastic material matrix for concrete based on Bresler–Pistercriterion
In the plasticity theory, total strain can be assumed to be thesum of the elastic strain and plastic strain as given in Eq. (11),and stress increment, drij, for strain increment, deij, is given inEq. (12) [15].
deij ¼ deeij þ dep
ij ð11Þdrij ¼ Dep
ijkldeij ð12Þ
where Depijkl is elastic–plastic material matrix. In the case of associ-
ated flow rule the general form of this matrix is given as,
Depijkl ¼ Dijkl þ Dp
ijkl ð13Þ
280 T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286
where Dijkl is the elastic material matrix of the element (see Section5), and
Dpijkl ¼ �
Dijkl@f@rij
@f@rpq
Dpqkl
hþ @f@rij
Dijkl@f@rkl
ð14Þ
where
h ¼ UHp @f@s
ð15Þ
where
U ¼ 1s@f@rij
rij ð16Þ
where s is von Mises effective stress s ¼ffiffiffiffiffiffiffi3J2
p� �and Hp is slope of
uniaxial stress–strain curve.The gradient @f
@rijcan be written as
@f@rij¼ @f@I1
@I1
@rijþ @f@J2
@J2
@rijþ @f@J3
@J3
@rij: ð17Þ
Taking the derivatives of Eq. (10) with respect to I1, J2 and J3, the fol-lowing equations can be obtained.
@f@I1¼ 2c
9f 02cI1 �
b3f 0c
@f@J2¼ � 1ffiffiffiffiffiffiffi
6J2
pf 0c
@f@J3¼ 0
ð18Þ
The gradient @I1@rij
and @J2@rij
are called to be the kronecker delta anddeviatoric stress tensor, respectively, and they are given in Eqs.(19) and (20), respectively.
@I1
@rij¼ dij ¼
1 0 00 1 00 0 1
264
375 ð19Þ
@J2
@rij¼ sij ¼ rij �
I1
3dij: ð20Þ
By substituting Eqs. (18)–(20) into Eq. (17), the following equationcan be obtained.
@f@rij¼ 2c
9f 02cI1 �
b3f 0c
� �dij �
1ffiffiffiffiffiffiffi6J2
pf 0c
!sij ð21Þ
The gradient @f@s based on Bresler–Pister criterion can be obtained,
and it is given below.
@f@s¼ �
ffiffiffi2p
3f 0c: ð22Þ
Strain, ε
Stre
ss, σ
K=1.0
K=1.2
K=1.4
K=1.6
K=1.8
K=2.0
σp
a
Fig. 1. Stress–strain curve of (a) Saenz and (b) elastic–per
4. Stress–strain curves for concrete
In order to define stress–strain relationship for concrete severalstress–strain curves are proposed by researchers [4,16–25]. TheSaenz [19] and elastic–perfectly plastic stress–strain relationshipused for the behavior of concrete in compression are given inEqs. (23) and (24), respectively, and they are given in Fig. 1.
rc ¼ rp
K ecep
� �� ec
ep
� �2
1þ A ecep
� �þ B ec
ep
� �2þ C ec
ep
� �3 ð23Þ
rc ¼ �ec
ep
� �rp if ep < ec < 0
rc ¼ �rp if ec < ep < 0ð24Þ
where
A ¼ C þ K � 2; B ¼ 1� 2C; C ¼ KðKr � 1ÞðKe � 1Þ2
� 1Ke
ð25Þ
K ¼ Eep
rp; Ke ¼
ef
ep; Kr ¼
rp
rfð26Þ
where ef and rf are the control point coordinates on descendingbranch of stress–strain curve, rc is concrete compressive stress, ec
is concrete compressive strain, rp is peak concrete compressivestress, ep is concrete compressive strain corresponding to rp, andE is modulus of elasticity of concrete.
The stress–strain curve of concrete in tension proposed byWang and Hsu [4] is shown in Fig. 2a. The ascending and descend-ing braches of this curve are given by the following equation.
rt ¼ Eet if et � ecr
rt ¼ rcrecr
et
� �0:4
if et > ecr
ð27Þ
where rt is concrete tensile stress, et is concrete tensile strain, rcr isconcrete cracking stress, and ecr is concrete cracking strain.
The other stress–strain curve of concrete in tension used in thispaper is Vecchio 1982 curve [26]. This curve is shown in Fig. 2b andits stress–strain relationship is given by the following equation.
rt ¼rcr
1þffiffiffiffiffiffiffiffiffiffiffiffiffi200etp if 0 < ecr < et ð28Þ
5. Material matrix of finite element
The material matrix of a finite element is constructed to be thesum of the material matrices of the concrete and reinforcement. Inthis calculation, the reinforcement embedded in the concrete ele-ments is represented by an equivalent element. The materialmatrices of concrete and reinforcement are given, respectively, as:
Strain, ε
Stre
ss, σ
σp
εp
b
fectly plastic model for concrete under compression.
Strain, ε
Stre
ss, σ
σcr
εcrStrain, ε
Stre
ss, σ
σcr
εcr
a b
Fig. 2. Stress–strain curve of: (a) Wang and Hsu [4] and (b) Vecchio 1982 model for concrete under tension.
T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286 281
½D� ¼ ½Dc� þ ½Ds� ¼E
1� v2
1 v 0v 1 00 0 ð1� vÞ=2
264
375þ
qxEs 0 00 qyEs 00 0 0
264
375
ð29Þ
where Dc and Ds are the material matrices of concrete and equiva-lent reinforcement elements, respectively, Es is the modulus of elas-ticity of reinforcement, qx and qy are the reinforcement ratios inglobal directions of the x and y axes, respectively.
6. Applications
The applicability and verification of the developed program aredemonstrated by comparing the results obtained in this study withthe experimental and analytical results of two different RC beams,Bresler–Scordelis beam and J4 beam, given below.
6.1. Bresler–Scordelis beam
The first RC member used to validate the program coded is Bres-ler–Scordelis beam. It is simply supported RC beam [4,27] and isshown in Fig. 3. The longitudinal reinforcement consists of foursteel bars with total area of 2580 mm2. The concrete has a com-pressive strength of 24.5 MPa and elastic modulus of 21,300 MPa.The elastic modulus of steel bars is 191,400 MPa.
In the finite element modeling, 4-noded rectangular plane-stress element is used. This element has two displacement degreesof freedom at a point and eight displacement degrees of freedom inan element. Perfect bond between concrete and reinforcement isassumed.
Since the method used herein is a numerical method, the finiteelement method, there is always some error in the results, depend-
Fig. 3. Bresler–Sco
ing on the mesh size used to solve the problem. Therefore, for thesake of accuracy in the results, rather than starting with a finiteelement mesh size, the mesh size to produce the desired accuracyis determined. To find out the required mesh size, convergence ofthe maximum displacement is checked for different mesh sizes.In conclusion, the results have an acceptable error when usingapproximately 70 elements. Therefore, 70 elements which is alsothe number of the elements used in the literature are used in thisstudy in order to compare the results obtained in this study withthe experimental and theoretical results given in the literature. Fi-nite element modeling of this beam is given in Fig. 4.
The results of the nonlinear analysis of this beam by using yieldfunction of Drucker–Prager criterion with two different tensionstress–strain curves ([4], Vecchio 1982) for the tension behaviorof concrete and with two different compression stress–straincurves (elastic–perfectly plastic and Saenz) for the compressionbehavior of concrete are given in Fig. 5. These results are comparedwith each other and with the experimental result taken from theliterature [4,27]. As seen from this figure, the load–displacementcurves obtained in this study are in good agreement with theexperimental result.
The results of the nonlinear analysis of this beam by using yieldfunction of von Mises criterion with two different tension stress–strain curves ([4], Vecchio 1982) for the tension behavior of con-crete and with two different compression stress–strain curves(elastic–perfectly plastic and Saenz) for the compression behaviorof concrete are given in Fig. 6. These results are compared witheach other and with the experimental result taken from the litera-ture [4,27]. As seen from this figure, the load–displacement curvesobtained in this study are in good agreement with the experimen-tal result.
The results of the nonlinear analysis of this beam by using yieldfunction of Mohr Coulomb criterion with two different tension
rdelis beam.
1,2, …, 88 : Node numbers
1 2 10
61 70
11 1 11 12
78 88
P
1828.8 mm
127
425
.5 m
m
1 2 70
2 3
, , …, : Element numbers
Fig. 4. Finite element modeling of Bresler–Scordelis beam.
0 2 4 6 8Displacement (mm)
0
100
200
300
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic perfectly plastic
Wand and Hsu (2001) Saenz
Vecchio 1982 Elastic perfectly plastic
Vecchio 1982 SaenzExperimental
Fig. 5. Load–displacement curves of Bresler–Scordelis beam for Drucker–Prager criterion.
Displacement (mm)
0
100
200
300
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic perfectly plastic
Wand and Hsu (2001) Saenz
Vecchio 1982 Elastic perfectly plastic
Vecchio 1982 SaenzExperimental
0 2 4 6 8 10
Fig. 6. Load–displacement curves of Bresler–Scordelis beam for von Mises criterion.
282 T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286
stress–strain curves ([4], Vecchio 1982) for the tension behavior ofconcrete and with two different compression stress–strain curves(elastic–perfectly plastic and Saenz) for the compression behaviorof concrete are given in Fig. 7. These results are compared witheach other and with the experimental result taken from the litera-ture [4,27]. As seen from this figure, the load–displacement curvesobtained in this study are in good agreement with the experimen-tal result.
The results of the nonlinear analysis of this beam by using yieldfunction of Bresler–Pister criterion with two different tension
stress–strain curves ([4], Vecchio 1982) for the tension behaviorof concrete and with two different compression stress–straincurves (elastic–perfectly plastic and Saenz) for the compressionbehavior of concrete are given in Fig. 8. These results are comparedwith each other and with the experimental result taken from theliterature [4,27]. As seen from this figure, the load–displacementcurves obtained in this study are in good agreement with theexperimental result.
In general, the results obtained using the compression models,tension models and the yield criteria considered in this study are
0 2 4 6 8 10Displacement (mm)
0
100
200
300
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic perfectly plastic
Wand and Hsu (2001) Saenz
Vecchio 1982 Elastic perfectly plastic
Vecchio 1982 SaenzExperimental
Fig. 7. Load–displacement curves of Bresler–Scordelis beam for Mohr Coulomb criterion.
Displacement (mm)
0
100
200
300
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic perfectly plastic
Wand and Hsu (2001) Saenz
Vecchio 1982 Elastic perfectly plastic
Vecchio 1982 SaenzExperimental
0 2 4 6 8
Fig. 8. Load–displacement curves of Bresler–Scordelis beam for Bresler–Pister criterion.
T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286 283
in good agreement with the experimental result. Especially, the re-sults of new criterion, Bresler–Pister, show excellent agreementwith the results obtained by using the other criteria and with theexperimental result.
6.2. Simply supported J4 beam
The second RC member used to validate the program coded is J4beam. It is simply supported [28,29] and is shown in Fig. 9. The lon-gitudinal reinforcement consists of two steel bars with total area of1021 mm2. The concrete has a compressive strength of 33 MPa andelastic modulus of 26,200 MPa. The elastic modulus of steel bars is203,000 MPa.
Fig. 9. J4 b
The finite element mesh convergence of this beam is also stud-ied. It is concluded that the results have an acceptable error whenusing approximately 45 elements. This element number is also thenumber of the elements used in the literature. Therefore, using thiselement number makes possible compare the results obtained inthis study with the experimental and theoretical results given inthe literature. Finite element modeling of this beam is given inFig. 10.
The results of the nonlinear analysis of this beam by using yieldfunction of Drucker–Prager criterion with two different tensionstress–strain curves ([4], Vecchio 1982) for the tension behaviorof concrete and with two different compression stress–straincurves (elastic–perfectly plastic and Saenz) for the compression
eam.
1 1 2 9
10
37 45
2 3 9 10 11
51 60
P
1850 mm
51
457
mm
Fig. 10. Finite element modeling of J4 beam.
0 2 4 6 8 10 12 14 16Displacement (mm)
0
40
80
120
160
200
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic Perfectly Plastic
Wang and Hsu (2001) Saenz
Vecchio 1982 Elastic Perfectly Plastic
Vecchio 1982 Saenz
Demir (1998) Barzegar and Schnobrich (1986) Experimental
Fig. 11. Load–displacement curves of J4 beam for Drucker–Prager criterion.
284 T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286
behavior of concrete are given in Fig. 11. These results are com-pared with each other and with the experimental [29] and analyt-ical results [28,30]. As seen from this figure, the load–displacementcurves obtained in this study are in good agreement with theexperimental and analytical results.
The results of the nonlinear analysis of this beam by using yieldfunction of von Mises criterion with two different tension stress–strain curves ([4], Vecchio 1982) for the tension behavior of con-crete and with two different compression stress–strain curves(elastic–perfectly plastic and Saenz) for the compression behaviorof concrete are given in Fig. 12. These results are compared witheach other and with the experimental [29] and analytical results[28,30]. As seen from this figure, the load–displacement curves ob-tained in this study are in good agreement with the experimentaland analytical results.
Displace
0
40
80
120
160
200
Loa
d (k
N)
0 2 4 6
Fig. 12. Load–displacement curves of
The results of the nonlinear analysis of this beam by using yieldfunction of Mohr Coulomb criterion with two different tensionstress–strain curves ([4], Vecchio 1982) for the tension behaviorof concrete and with two different compression stress–straincurves (elastic–perfectly plastic and Saenz) for the compressionbehavior of concrete are given in Fig. 13. These results are com-pared with each other and with the experimental [29] and analyt-ical results [28,30]. As seen from this figure, the load–displacementcurves obtained in this study are in good agreement with theexperimental and analytical results.
The results of the nonlinear analysis of this beam by using yieldfunction of Bresler–Pister criterion with two different tensionstress–strain curves ([4], Vecchio 1982) for the tension behaviorof concrete and with two different compression stress–straincurves (elastic–perfectly plastic and Saenz) for the compression
ment (mm)
This study Tension model Compression model
Wang and Hsu (2001) Elastic Perfectly Plastic
Wang and Hsu (2001) Saenz
Vecchio 1982 Elastic Perfectly Plastic
Vecchio 1982 Saenz
Demir (1998) Barzegar and Schnobrich (1986) Experimental
8 10 12 14 16
J4 beam for von Mises criterion.
0 2 4 6 8 10 12 14 16Displacement (mm)
0
40
80
120
160
200
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic Perfectly Plastic
Wang and Hsu (2001) Saenz
Vecchio 1982 Elastic Perfectly Plastic
Vecchio 1982 Saenz
Demir (1998) Barzegar and Schnobrich (1986) Experimental
Fig. 13. Load–displacement curves of J4 beam for Mohr Coulomb criterion.
Displacement (mm)
0
40
80
120
160
200
Loa
d (k
N)
This study Tension model Compression model
Wang and Hsu (2001) Elastic Perfectly Plastic
Wang and Hsu (2001) Saenz
Vecchio 1982 Elastic Perfectly Plastic
Vecchio 1982 Saenz
Demir (1998) Barzegar and Schnobrich (1986) Experimental
0 2 4 6 8 10 12 14 16
Fig. 14. Load–displacement curves of J4 beam for Bresler–Pister criterion.
T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286 285
behavior of concrete are given in Fig. 14. These results are com-pared with each other and with the experimental [29] and analyt-ical results [28,30]. As seen from this figure, the load–displacementcurves obtained in this study are in good agreement with theexperimental and analytical results.
In generally, the results obtained using the compression mod-els, tension models and the yield criteria considered in this studyare in good agreement with the experimental and analytical re-sults. Especially, the results of new criterion, Bresler–Pister, showexcellent agreement with the results obtained by using the othercriteria and with the experimental and analytical results.
7. Conclusions
Analytical models are presented for the nonlinear finite elementanalysis of reinforced concrete structures. Based on the Bresler–Pister yield function, a plastic material matrix for concrete materialis constructed. Also, different stress–strain curves of concrete fortension and compression behavior are taken into account and thewell-known criteria, Drucker–Prager, von Mises and Mohr Cou-lomb are also used for the plastic behavior of concrete.
The computer program coded in this study is useful for predict-ing the behavior of reinforced concrete structures. This programcontains the well-known criteria (Drucker–Prager, von Mises, andMohr Coulomb), a new criterion (Bresler–Pister), stress–straincurves for the compression behavior of concrete (elastic–perfectlyplastic and Saenz model), and tension stiffening model ([4], Vec-chio 1982 model).
The proposed models and Bresler–Pister criterion can be effec-tively used in nonlinear analysis of reinforced concrete beams.
References
[1] Ayoub A, Filippou FC. Nonlinear finite-element analysis of RC shear panels andwalls. J Struct Eng 1998;124(3):298–308.
[2] Arslan G. Sensitivity study of the Drucker–Prager modeling parameters in theprediction of the nonlinear response of reinforced concrete structures. MaterDes 2007;28:2596–603.
[3] Park H, Klingner RE. Nonlinear analysis of RC members using plasticity withmultiple failure criteria. J Struct Eng 1997;123(5):643–56.
[4] Wang T, Hsu TTC. Nonlinear finite element analysis of concrete structuresusing new constitutive models. Comput Struct 2001;79:2781–91.
[5] Bratina S, Saje M, Planinc I. On materially and geometrically nonlinear analysisof reinforced concrete planar frames. Int J Solids Struct 2004;41:7181–207.
[6] Zhao ZZ, Kwan AKH, He XG. Nonlinear finite element analysis of deepreinforced concrete coupling beams. Eng Struct 2004;26:13–25.
[7] Pankaj P, Lin E. Material modeling in the seismic response analysis for thedesign of RC frames structures. Eng Struct 2005;27:1014–23.
[8] Belmouden Y, Lestuzzi P. Analytical model for predicting nonlinear reversedcyclic behavior of reinforced concrete structural walls. Eng Struct2007;29:1263–76.
[9] Bitchoff PH. Effects of shrinkage on tension stiffening and cracking inreinforced concrete. Can J Civil Eng 2001;28:363–74.
[10] Bitchoff PH. Tension stiffening and cracking of steel fiber-reinforced concrete. JMater Civil Eng 2003;15(2):174–82.
[11] Stramandinoli RSB, Rovere HLL. An efficient tension-stiffening model fornonlinear analysis of reinforced concrete members. Eng Struct2008;30:2069–80.
[12] Dede T, Ayvaz Y. Nonlinear analysis of reinforced concrete beam with/withouttension stiffening effect. Mater Des. doi:10.1016/j.matdes.2009.02.003.
[13] Bresler B, Pister KS. Strength of concrete under combined stresses. J Am ConcrInst 1958;55:321–45.
[14] Chen WF. Plasticity in reinforced concrete. New York: McGraw-Hill; 1982.
286 T. Dede, Y. Ayvaz / Materials and Design 31 (2010) 278–286
[15] Chen WF. Constitutive equation for engineering materials. New York: Elsevier;1994.
[16] Hognestad E. A study of combined and axial load in reinforced concretemembers. Bulletin series, vol. 399. University of Illinois Engineering Station;1951. p. 1.
[17] Popovics S. A numerical approach to the complete stress–strain curve ofconcrete. Cem Concr Res 1973;3(5):583–99.
[18] Collins MP, Porasz A. Shear design of high strength concrete. CEB Bull d’ Inform1989;193:77–83.
[19] Saenz LP. Discussion of equation for the stress–strain curve of concrete byDesayi and Krishnan. Am Concr Inst J 1964;61(3):1229–35.
[20] Hoshikuma J, Kazuhiko K, Kazuhiko N, Taylor AW. A model for confinementeffect on stress–strain relation of reinforced concrete columns for seismicdesign. In: Proceedings of the 11th World conference on earthquakeengineering. London: Elseiver Science; 1996. p. 825.
[21] Park R, Paulay T. Reinforced concrete structures. United States ofAmerica: John Wiley & Sons, Inc.; 1975.
[22] Desayi P, Krishnan S. Equation for the stress–strain curve of concrete. ACI J1964;61:345–50.
[23] Bentz EC. Sectional analysis of reinforced concrete members. Ph.D. Thesis.University of Toronto; 1999.
[24] Izumo J, Shin H, Maekawa K, Okamura H. An analytical model for RC panelssubjected to in-plane stresses. Concr Shear Earthq 1992:206–15.
[25] Turgay T, Köksal HO, Polat Z, Karakoç C. Stress–strain model for concreteconfined with CFRP jackets. Mater Des. doi:10.1016/j.matdes.2008.11.022.
[26] Wong PSL. User facilities for 2D nonlinear finite element analysis of reinforcedconcrete. M.Sc. Thesis. University of Toronto; 2002.
[27] Bresler B, Scordelis AC. Shear strength of reinforced concrete beams – series II.SESM Report No. 64-2. University of California, Berkeley; 1964.
[28] Demir F. Applications of finite element in reinforced concrete elements. Ph.D.Thesis. Istanbul Technical University; 1998 [in Türkish].
[29] Burns NH, Siess CP. Load–deformations characteristics of beam–columnconnections in reinforced concrete. Civil Engineering Studies. SRS No. 243.University of Illinois, Urbana; 1962.
[30] Barzegar F, Schnobrich WC. Nonlinear finite element analysis of RC under shortterm monotonic loading. Civil Engineering Studies. SRS No.530. University ofIllinois, Urbana; 1962.