Stress Density Material

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This command is used to construct a multi-dimensional stress density material object for modeling sand behaviour following the work of Cubrinovski and Ishihara (1998a,b).

nDMaterial StressDensityModel $matTag $mDen $eNot $A $n $nu $a1 $b1 $a2 $b2 $a3 $b3 $fd $muNot $muCyc $sc $M $patm <$ssl1 $ssl2 $ssl3 $ssl4 $ssl5 $ssl6 $ssl7 $ssl8 $ssl9 $ssl10 $hsl $p1 $p2 $p3 $p4 $p5 $p6 $p7 $p8 $p9 $p10>

$matTag	integer tag identifying material
$mDen	mass density
$eNot	initial void ratio
$A	constant for elastic shear modulus
$n	pressure dependency exponent for elastic shear modulus
$nu	Poisson's ratio
$a1	peak stress ratio coefficient (etaMax = a1 + b1*Is)
$b1	peak stress ratio coefficient (etaMax = a1 + b1*Is)
$a2	max shear modulus coefficient (Gn_max = a2 + b2*Is)
$b2	max shear modulus coefficient (Gn_max = a2 + b2*Is)
$a3	min shear modulus coefficient (Gn_min = a3 + b3*Is)
$b3	min shear modulus coefficient (Gn_min = a3 + b3*Is)
$fd	degradation constant
$muNot	dilatancy coefficient (monotonic loading)
$muCyc	dilatancy coefficient (cyclic loading)
$sc	dilatancy strain
$M	critical state stress ratio
$patm	atmospheric pressure (in appropriate units)
<$ssl1>	void ratio of quasi steady state (QSS-line) at pressure $p1 (default = 0.877)
<$ssl2>	void ratio of quasi steady state (QSS-line) at pressure $p2 (default = 0.877)
<$ssl3>	void ratio of quasi steady state (QSS-line) at pressure $p3 (default = 0.873)
<$ssl4>	void ratio of quasi steady state (QSS-line) at pressure $p4 (default = 0.870)
<$ssl5>	void ratio of quasi steady state (QSS-line) at pressure $p5 (default = 0.860)
<$ssl6>	void ratio of quasi steady state (QSS-line) at pressure $p6 (default = 0.850)
<$ssl7>	void ratio of quasi steady state (QSS-line) at pressure $p7 (default = 0.833)
<$ssl8>	void ratio of quasi steady state (QSS-line) at pressure $p8 (default = 0.833)
<$ssl9>	void ratio of quasi steady state (QSS-line) at pressure $p9 (default = 0.833)
<$ssl10>	void ratio of quasi steady state (QSS-line) at pressure $p10 (default = 0.833)
<$hsl>	void ratio of upper reference state (UR-line) for all pressures (default = 0.895)
<$p1>	pressure corresponding to $ssl1 (default = 1.0 kPa)
<$p2>	pressure corresponding to $ssl1 (default = 10.0 kPa)
<$p3>	pressure corresponding to $ssl1 (default = 30.0 kPa)
<$p4>	pressure corresponding to $ssl1 (default = 50.0 kPa)
<$p5>	pressure corresponding to $ssl1 (default = 100.0 kPa)
<$p6>	pressure corresponding to $ssl1 (default = 200.0 kPa)
<$p7>	pressure corresponding to $ssl1 (default = 400.0 kPa)
<$p8>	pressure corresponding to $ssl1 (default = 400.0 kPa)
<$p9>	pressure corresponding to $ssl1 (default = 400.0 kPa)
<$p10>	pressure corresponding to $ssl1 (default = 400.0 kPa)

The material formulations for the StressDensity object are "ThreeDimensional" and "PlaneStrain"

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Code Developed by Saumyashuchi Das, University of Canterbury. Maintained by Chris McGann

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General Information

This nDMaterial object provides the