uniaxialMaterial('Dodd_Restrepo', matTag, Fy, Fsu, ESH, ESU, Youngs, ESHI, FSHI, OmegaFac=1.0)

This command is used to construct a Dodd-Restrepo steel material

matTag (int) integer tag identifying material
Fy (float) Yield strength
Fsu (float) Ultimate tensile strength (UTS)
ESH (float) Tensile strain at initiation of strain hardening
ESU (float) Tensile strain at the UTS
Youngs (float) Modulus of elasticity
ESHI (float) Tensile strain for a point on strain hardening curve, recommended range of values for ESHI: [ (ESU + 5*ESH)/6, (ESU + 3*ESH)/4]
FSHI (float) Tensile stress at point on strain hardening curve corresponding to ESHI
OmegaFac (float) Roundedness factor for Bauschinger curve in cycle reversals from the strain hardening curve. Range: [0.75, 1.15]. Largest value tends to near a bilinear Bauschinger curve. Default = 1.0.

See also