This document describes an algorithm for analyzing concrete cracks in ANSYS. It defines four stress states for concrete sections: P (partially in compression/tension), T (completely in tension), C (completely in compression), and P* (a special case of P). It provides examples comparing the algorithm's analytic solutions to numerical solutions in ANSYS for each stress state, demonstrating good agreement. The document also shows how the algorithm outputs crack widths and orientations.
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EC2 Concrete Crack Algorithm
1. Dong LI Crack March 14, 2017 1 / 34
Concrete Crack Algorithme in ANSYS
Structure&Optimazation
Dong LI
March 14, 2017
2. Introduction
The programme is a post-treatment propramme in ANSYS APDL
Language dedicated to ANSYS concrete structural FE model analysis.
The programme is aimed to computer concrete shell and beam crack
and carry out SLS concrete and rebars stress veri?cation according to
European concrete code -Eurocode 2.
It can dealt with general case like As = As and give the section stress
state noting as P -Section partially in compression/tension, T
-Section completely in tension, C -Section completely in compression
and P? -Special case for section completely in compression.
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3. Four Con?gurations
Four concrete section stress states are de?ned in algorithm.
A¨s
As
x
A¨s F¨
As F
A¨s
As
x
A¨s
As
h
d
x
They are noted separately in programme:
1 P
2 T
3 C
4 P*
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4. Special Case - P*
De?nition (P*)
h ? d + x < h
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5. Special Case - C
De?nition (C)
|
M
N
| +
h
6
if As = As (a)
|
M
N
| + f (i, s) if As = As (b)
As = As is a special case of (b).
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7. Analytic vs. Numerical Case P
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1MN M ?0.5MNm
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8. Analytic vs. Numerical Case P
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1MN M ?0.5MNm
? Result
Analytic Algorithm
wk 1.252 1.252 mm
x 0.1083 0.1083 m
σs 20.02 20.022 MPa
σs 365.82 365.818 MPa
σc 3.48 3.475 MPa
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10. Analytic vs. Numerical Case P
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N 1MN M 0.25MNm
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11. Analytic vs. Numerical Case P
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N 1MN M 0.25MNm
? Result
Analytic Algorithm
wk 0.01 0.011 mm
x 0.584 0.5839 m
σs 13.49 13.489 MPa
σs 48.54 48.537 MPa
σc 3.01 3.013 MPa
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13. Analytic vs. Numerical Case T
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1MN M 0.15MNm
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14. Analytic vs. Numerical Case T
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1MN M 0.15MNm
? Result
Analytic Algorithm
wk 0.26 0.261 mm
x m
σs ?212.58 ?212.577 MPa
σs ?78.46 ?78.459 MPa
σc MPa
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16. Analytic vs. Numerical Case C
A¨s
As
b
h
d
d¨
? Input data
h 0.6 As 9.42cm2 Ecm 10.83GPa
b 0.3 As 9.42cm2 fctm 3MPa
d 0.05 Bar 3HA20 k1 0.8
d 0.05 Es 200GPa k4 0.425
kt 0.4 fyd 435MPa fcd 16.7MPa
N 1.14MN M 0.11MNm
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17. Analytic vs. Numerical Case C
A¨s
As
b
h
d
d¨
? Input data
h 0.6 As 9.42cm2 Ecm 10.83GPa
b 0.3 As 9.42cm2 fctm 3MPa
d 0.05 Bar 3HA20 k1 0.8
d 0.05 Es 200GPa k4 0.425
kt 0.4 fyd 435MPa fcd 16.7MPa
N 1.14MN M 0.11MNm
? Result
Analytic Algorithm
wk mm
x m
σs 24.5 24.547 MPa
σs 139.6 139.67 MPa
σc 0.87 0.869 MPa
σc 10.07 10.079 MPa
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19. Analytic vs. Numerical Case P*
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N 0.01836 M ?0.00297 MNm
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20. Analytic vs. Numerical Case P*
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N 0.01836 M ?0.00297 MNm
? Result
Analytic Algorithm
wk ?0.00 ?0.175E ? 3 mm
x 0.77 0.7726 m
σs 0.69 0.685 MPa
σs ?0.046 ?0.0462 MPa
σc 41.0E ? 3 41.03E ? 3 MPa
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21. Analytic vs. Numerical Case As = A s
A¨s
As
b
h
d
d¨
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22. Analytic vs. Numerical Case As = A s
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 40.21cm2 fctm 3MPa
d 0.0745 Bar HA25/32 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1 M ?0.5 MNm
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23. Analytic vs. Numerical Case As = A s
A¨s
As
b
h
d
d¨
? Input data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 40.21cm2 fctm 3MPa
d 0.0745 Bar HA25/32 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
N ?1 M ?0.5 MNm
? Result
Analytic Algorithm
wk 1.06 1.0631 mm
x 0.12 0.1156 m
σs 21.322 21.322 MPa
σs 316.71 316.71 MPa
σc 3.25 3.249 MPa
Dong LI Crack March 14, 2017 11 / 34
25. Input Data
A¨s
As
b
h
d
d¨
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
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27. ANSYS Model Element Number
Figure: Element Number Presentation
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28. ANSYS Model Result Presentation
Figure: Crack Width in Y direction Top Face -mm
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29. ANSYS Model Result Presentation
Figure: Crack Width in X direction Top Face -mm
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30. ANSYS Model Result Presentation
Figure: Crack Width in Y direction Bottom Face -mm
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31. ANSYS Model Result Presentation
Figure: Crack Width in X direction Bottom Face -mm
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32. Output Data
Elem x1 x2 wkx-bot wky-bot wkx-top wky-top xDir yDir
1. 0.49 0.80 0.00 0.00 0.00 0.00 P C
2. 0.80 0.36 0.00 0.00 0.00 0.00 C P
3. 0.80 0.28 0.00 0.00 0.00 0.01 C P
4. 0.68 0.27 0.00 0.00 0.00 0.01 P P
5. 0.53 0.26 0.00 0.00 0.00 0.02 P P
6. 0.42 0.26 0.00 0.00 0.00 0.02 P P
7. 0.36 0.26 0.00 0.00 0.00 0.03 P P
8. 0.31 0.26 0.00 0.00 0.00 0.03 P P
9. 0.28 0.26 0.00 0.00 0.01 0.04 P P
10. 0.26 0.26 0.00 0.00 0.01 0.04 P P
11. 0.24 0.26 0.00 0.00 0.01 0.04 P P
12. 0.20 0.22 0.00 0.00 0.01 0.06 P P
13. 0.38 0.80 0.00 0.00 0.00 0.00 P C
14. 0.57 0.46 0.00 0.00 0.00 0.00 P P
15. 0.77 0.33 0.00 0.00 0.00 0.00 P* P
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33. ANSYS Model Result Presentation - Stress
Figure: Concrete Stress Y direction Top Face -Mpa
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34. ANSYS Model Result Presentation - Stress
Figure: Concrete Stress X direction Top Face -Mpa
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35. ANSYS Model Result Presentation - Stress
Figure: Concrete Stress Y direction Bottom Face -Mpa
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36. ANSYS Model Result Presentation - Stress
Figure: Concrete Stress X direction Bottom Face -Mpa
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37. ANSYS Model Result Presentation - Stress
Elem x1 x2 CX-b CY-b CX-T CY-T x y
1. 0.49 0.80 0.02 0.02 0.00 0.01 P C
2. 0.80 0.36 0.03 0.04 0.00 0.00 C P
3. 0.80 0.28 0.03 0.10 0.00 0.00 C P
4. 0.68 0.27 0.04 0.17 0.00 0.00 P P
5. 0.53 0.26 0.05 0.24 0.00 0.00 P P
6. 0.42 0.26 0.06 0.31 0.00 0.00 P P
7. 0.36 0.26 0.08 0.38 0.00 0.00 P P
8. 0.31 0.26 0.09 0.44 0.00 0.00 P P
9. 0.28 0.26 0.10 0.49 0.00 0.00 P P
10. 0.26 0.26 0.11 0.54 0.00 0.00 P P
11. 0.24 0.26 0.11 0.58 0.00 0.00 P P
12. 0.20 0.22 0.06 0.57 0.00 0.00 P P
13. 0.38 0.80 0.09 0.03 0.00 0.00 P C
14. 0.57 0.46 0.06 0.04 0.00 0.00 P P
15. 0.77 0.33 0.04 0.07 0.00 0.00 P* P
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38. ANSYS Model Result Presentation - Stress
Figure: Bar Stress Y direction Top Face -Mpa
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39. ANSYS Model Result Presentation - Stress
Figure: Bar Stress X direction Top Face -Mpa
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40. ANSYS Model Result Presentation - Stress
Figure: Bar Stress Y direction Bottom Face -Mpa
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41. ANSYS Model Result Presentation - Stress
Figure: Bar Stress X direction Bottom Face -Mpa
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42. ANSYS Model Result Presentation - Stress
Elem x1 x2 SX-b SY-b SX-T SY-T x y
1. 0.49 0.80 0.38 0.32 0.22 0.21 P C
2. 0.80 0.36 0.43 0.55 0.08 0.72 C P
3. 0.80 0.28 0.51 1.29 0.07 2.77 C P
4. 0.68 0.27 0.64 2.22 0.05 5.22 P P
5. 0.53 0.26 0.80 3.19 0.35 7.80 P P
6. 0.42 0.26 0.97 4.11 0.84 10.30 P P
7. 0.36 0.26 1.12 4.96 1.47 12.62 P P
8. 0.31 0.26 1.24 5.72 2.16 14.72 P P
9. 0.28 0.26 1.34 6.41 2.88 16.55 P P
10. 0.26 0.26 1.43 7.08 3.55 17.99 P P
11. 0.24 0.26 1.39 7.65 3.96 19.07 P P
12. 0.20 0.22 0.69 6.99 3.02 24.44 P P
13. 0.38 0.80 1.29 0.51 1.50 0.10 P C
14. 0.57 0.46 0.91 0.60 0.29 0.42 P P
15. 0.77 0.33 0.68 0.97 -0.05 1.49 P* P
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43. Analytic Solution-Element 15
A¨s
As
h
xInput data
h 0.8 As 34.36cm2 Ecm 10.83GPa
b 1 As 34.36cm2 fctm 3MPa
d 0.0745 Bar 7HA25 k1 0.8
d 0.0745 Es 200GPa k4 0.425
kt 0.4 fyd 250MPa fcd 21MPa
Elem 15
Nx 18.36KN Mx ?2.97KNm
Ny 9.35KN My ?5.08
Elem 3
Nx 14.588KN Mx ?2.07KNm
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44. Analytic Solution-Element 15 - Direction X
A¨s
As
h
0.77
? Section stress statu ?★ P?
? y3 + p , y + q = 0 ?★ x = 0.77
p = ?0.469E ? 01
q = ?0.128
? σb = N,x
b,x2
2
?Es /Ec ,As ,(d?x)?Es /Ec ,As ,(x?d )
?★ σ = 41.03Kpa
? σs = Es/Ec , σb , d?x
x ?★ σs = 0.685Mpa
? σs = Es/Ec , σb , x?d
x ?★ σs = ?0.05Mpa
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45. Analytic Solution-Element 15 - Direction Y
A¨s
As
x
? Section stress statu ?★ P
? y3 + p , y + q = 0 ?★ x = 0.3304
p = 0.3148
q = ?0.3647
? σb = N,x
b,x2
2
?Es /Ec ,As ,(d?x)?Es /Ec ,As ,(x?d )
?★ σ = 0.067Kpa
? σs = Es/Ec , σb , d?x
x ?★ σs = 0.965Mpa
? σs = Es/Ec , σb , x?d
x ?★ σs = 1.49Mpa
? wk = 0.273e ? 2mm
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46. Analytic Solution-Element 3 - Direction X
A¨s
As
x
? Section stress statu ?★ C
? S = 0.9269m2
v = 0.4m
I = 0.0561m4
? σc = 0.98Kpa
? σc = 30.5Kpa
? σs = 68.9Kpa
? σs = 512.4Kpa
? wk = 0mm
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