Shear LimitCurve: Difference between revisions

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This command is used to construct an axial limit curve object that is used to define the point of axial failure for a LimitStateMaterial object. Point of axial failure based on model from Chapter 3. After axial failure response of LimitStateMaterial is forced to follow axial limit curve.
This command is used to construct a shear limit curve object that is used to define the point of shear failure for a LimitStateMaterial object. Point of shear failure is based on empirical drift capacity model from Chapter 2 of PEER 2003/01 report. After shear failure the response of LimitStateMaterial is forced to follow shear limit curve.




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| ''' $d''' || effective column depth (in.)
| ''' $d''' || effective column depth (in.)
|-
|-
| ''' $Fsw''' || loating point value describing the amount of transverse reinforcement <math>(F_{sw} = \frac{A_{st}f_{yt}d_c}{s})</math>
| ''' $Fsw''' || floating point value describing the amount of transverse reinforcement <math>(F_{sw} = \frac{A_{st}f_{yt}d_c}{s})</math>
|-
|-
| '''$Kdeg''' || If positive: unloading stiffness of beam-column element (Kunload from Figure 4-8)
| '''$Kdeg''' || If positive: unloading stiffness of beam-column element (Kunload from Figure 4-8)
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|-
|-
| '''%Fres'''' || floating point value for the residual force capacity of the post-failure backbone (see Figure 4-6)
| '''%Fres'''' || floating point value for the residual force capacity of the post-failure backbone (see Figure 4-6)
|-
|-
|-
|  '''$defType''' || integer flag for type of deformation defining the abscissa of the limit curve
|  '''$defType''' || integer flag for type of deformation defining the abscissa of the limit curve
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2 = drift based on displacment of nodes ndI and ndJ
2 = drift based on displacment of nodes ndI and ndJ
|-
|-
|  '''$forType''' || nteger flag for type of force defining the ordinate of the limit curve. See NOTES 1.
|-
|  '''$forType''' || integer flag for type of force defining the ordinate of the limit curve. See NOTES 1.


0 = force in associated limit state material
0 = force in associated limit state material
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2 = axial load in beam-column element
2 = axial load in beam-column element
|-
|-
|-
|  '''$ndI''' || nteger node tag for the first associated node
|  '''$ndI''' || nteger node tag for the first associated node
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EXAMPLE:
EXAMPLE:


<tcl>CenterColAxialSpring.tcl</tcl>
<tcl>CenterColShearSpring.tcl</tcl>


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Modeling Failures in Existing Reinforced Concrete Columns by Ken Elwood: [[file:ElwoodCJCE2004.pdf]]  
Modeling Failures in Existing Reinforced Concrete Columns by Ken Elwood: [[file:ElwoodCJCE2004.pdf]]  
----
WARNING:
UNITS TO BE ENTERED AS ABOVE and REQUIRE UNITS OF MODEL AS A WHOLE TO BE SAME.


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Latest revision as of 15:24, 12 September 2023



This command is used to construct a shear limit curve object that is used to define the point of shear failure for a LimitStateMaterial object. Point of shear failure is based on empirical drift capacity model from Chapter 2 of PEER 2003/01 report. After shear failure the response of LimitStateMaterial is forced to follow shear limit curve.


limitCurve Shear $curveTag $eleTag $rho $fc $b $h $d $Fsw $Kdeg $Fres $defType $forType <$ndI $ndJ $dof $perpDirn $delta>
$curveTag unique LimitCurve tag
$eleTag integer element tag for the associated beam-column element
$rho transverse reinforcement ratio <math>(\frac{A_{st}}{bh})</math>
$fc concrete compressive strength (psi)
$b column width (in.)
$h full column depth (in.)
$d effective column depth (in.)
$Fsw floating point value describing the amount of transverse reinforcement <math>(F_{sw} = \frac{A_{st}f_{yt}d_c}{s})</math>
$Kdeg If positive: unloading stiffness of beam-column element (Kunload from Figure 4-8)

if negative: slope of third branch of post-failure backbone (see Figure 4-6)

%Fres' floating point value for the residual force capacity of the post-failure backbone (see Figure 4-6)
$defType integer flag for type of deformation defining the abscissa of the limit curve

1 = maximum beam-column chord rotations

2 = drift based on displacment of nodes ndI and ndJ

$forType integer flag for type of force defining the ordinate of the limit curve. See NOTES 1.

0 = force in associated limit state material

1 = shear in beam-column element

2 = axial load in beam-column element

$ndI nteger node tag for the first associated node

(normally node I of $eleTag beam-column element)

$ndJ integer node tag for the second associated node

(normally node J of $eleTag beam-column element)

$dof nodal degree of freedom to monitor for drift. See NOTES 2
$perpDirn perpendicular global direction from which length is determined to compute drift. See Notes 2.
$delta drift (floating point value) used to shift axial limit curve


NOTES:

  1. Options 1 and 2 assume no member loads
  2. 1 = X, 2 = Y, 3 = Z

EXAMPLE:

<tcl>CenterColShearSpring.tcl</tcl>


DESCRIPTION:

Modeling Failures in Existing Reinforced Concrete Columns by Ken Elwood: File:ElwoodCJCE2004.pdf

WARNING:

UNITS TO BE ENTERED AS ABOVE and REQUIRE UNITS OF MODEL AS A WHOLE TO BE SAME.


REFERENCES:

Elwood, K.J and Moehle, J.P., "Shake Table Tests and Analystical Studies on the Gravity Load Collapse of Reinforced Concrete Frames", Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA. PEER 2003/01.


Code Developed by: Ken Elwood, University of British Columbia

Retrieved from "https://opensees.ist.berkeley.edu/wiki/index.php?title=Shear_LimitCurve&oldid=16438"