ReinforcingSteel

A reinforcing bar material: elastic to yield, a yield plateau, then a curved strain-hardening branch up to the ultimate strength.

🔧 Grasshopper component

ReinforcingSteelAlpaca4d ▸ MomentCurvature_βeta

Inputs

Defaults are B450C.

MatNameMaterial NameTextB450CLabel for the material.

fyNumber450000Yield strength, in kN/m².

fuNumber540000Ultimate strength, in kN/m².

EsNumber200000000Initial elastic modulus, in kN/m².

EshNumber2000000Tangent modulus at the onset of strain hardening, in kN/m².

Must be greater than zero.

eshNumber0.008Strain at the onset of strain hardening.

Must be past the yield strain fy/Es.

eultNumber0.075Strain at fu.

MinMaxBooleanfalseWrap the material so a bar fails once its strain passes eult in either direction.

Outputs

MaterialMaterialUniaxial material, for a Layer, Fiber Point or Patch.

This is the default material for Fiber Point and Layer Fiber — leave their Material input empty and they use B450C.

📈 When to use it

Use it when

• The fibres are reinforcing bars. The yield plateau and the curved hardening branch are what distinguish a bar from a structural steel section, and they set where the moment–curvature curve flattens.

Do not use it when

• The fibre is structural steel → Steel01 is simpler and more appropriate.

💡 MinMax

With MinMax on, a bar that strains past eult stops carrying stress — bar rupture. This is what puts an honest end on a moment–curvature curve; without it the section keeps resisting after its reinforcement should have broken.

Turn it on, together with Concrete01's, for any curve you intend to read a failure point off.

🔗 Relation to OpenSees

uniaxialMaterial ReinforcingSteel $matTag $fy $fu $Es $Esh $esh $eult
uniaxialMaterial MinMax           $wrapTag $matTag -min $minStrain -max $maxStrain