3.1.5.2. Steel02 Material

This command is used to construct a uniaxial Giuffre-Menegotto-Pinto steel material object with isotropic strain hardening.

uniaxialMaterial Steel02 $matTag $Fy $E $b $R0 $cR1 $cR2 <$a1 $a2 $a3 $a4 $sigInit>

Argument

Type

Description

$matTag

integer

integer tag identifying material

$Fy

float

yield strength

$E0

float

initial elastic tangent

$b

float

strain-hardening ratio (ratio between post-yield tangent and initial elastic tangent)

R0 $CR1 $CR2

3 float

parameters to control the transition from elastic to plastic branches.

$a1

float

isotropic hardening parameter. (optional: default = 0.0). see note.

$a2

float

isotropic hardening parameter (optional: default = 1.0). see note.

$a3

float

isotropic hardening parameter. (optional: default = 0.0). see note.

$a4

float

isotropic hardening parameter. (optional: default = 1.0). see note.

$sigInit

float

Initial Stress Value (optional: default = 0.0)

Note

$a1 and $a2: increase of compression yield envelope as proportion of yield strength after a plastic strain of $a2*($Fy/E0).

$a3 and $a4: increase of tension yield envelope as proportion of yield strength after a plastic strain of $a4*($Fy/E0).

Recommended values: $R0=between 10 and 20, $cR1=0.925, $cR2=0.15

If $siginit is specified, strain is calculated from epsP=$sigInit/$E

if (sigInit!= 0.0) {
   double epsInit = sigInit/E;
   eps = trialStrain+epsInit;
} else {
   eps = trialStrain;
}
FilippouEtAl1983

Filippou, F. C., Popov, E. P., Bertero, V. V. (1983). “Effects of Bond Deterioration on Hysteretic Behavior of Reinforced Concrete Joints”. Report EERC 83-19, Earthquake Engineering Research Center, University of California, Berkeley.

../../../../_images/Steel02Monotonic.jpg

Fig. 3.1.5.5 Steel02 Material – Material Parameters of Monotonic Envelope

../../../../_images/Steel02HystereticA.jpg

Fig. 3.1.5.6 Steel02 Material – Default Hysteretic Behavior (NO isotropic hardening)

Example

The following is used to construct a Steel02 mataerial with a tag of 1, a yield strength of $60.0** and an initial tangent stiffness of 30000,0.

  1. Tcl Code

uniaxialMaterial Steel02 60.0 30000.0 0.1 20.0 .925 .15
  1. Python Code

uniaxialMaterial('Steel02',60.0,30000.0, 0.1, 20.0, .925, .15)

Code Developed by: Michael H. Scott