Shear 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 based on empirical drift capacity model from Chapter 2.

limitCurve Shear $curveTag $eleTag $rho $fc $b $h $d $Fsw $Kdeg $Fres $defType $forType <$ndI $ndJ $dof $perpDirn $delta>.

$curveTag	unique limit curve object integer tag
$eleTag	integer element tag for the associated beam-column element
$rho	transverse reinforcement ratio (A_st/bh)
$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 (F_sw = A_stf_ytd_c/s)
$Kdeg	If positive: unloading stiffness of beam-column element (K_unload 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* 0 = force in associated limit state material 1 = shear in beam-column element
$ndI	integer 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**
$perpDirn	perpendicular global direction from which length is determined to compute drift**
$delta	drift (floating point value) used to shift shear limit curve

NOTE: * Option 1 assumes no member loads.
** 1 = X, 2 = Y, 3 = Z