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.
{{CommandManualMenu}}
 
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.




{|  
{|  
| style="background:yellow; color:black; width:800px" | '''limitCurve Axial $curveTag $eleTag $Fsw $Kdeg $Fres $defType $forType <$ndI $ndJ $dof $perpDirn $delta>'''
| style="background:yellow; color:black; width:800px" | '''limitCurve Shear $curveTag $eleTag $rho $fc $b $h $d $Fsw $Kdeg $Fres $defType $forType <$ndI $ndJ $dof $perpDirn $delta>'''
|}
|}


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|  '''$eleTag''' || integer element tag for the associated beam-column element
|  '''$eleTag''' || integer element tag for the associated beam-column element
|-
|-
|  '''$Fsw''' || floating point value describing the amount of transverse reinforcement <math>(F_{sw} = \frac{A_{st}f_{yt}d_c}{s})</math>
|  '''$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)
|-
|-
| '''$Kdeg''' || floating point value for the slope of the third branch in the post-failure backbone, assumed to be negative (see Figure 4-6)
| '''%Fres'''' || floating point value for the residual force capacity of the post-failure backbone (see Figure 4-6)
|-
|-
|  '''$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.


----
----

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"