Hyperbolic Gap MaterialΒΆ

uniaxialMaterial('HyperbolicGapMaterial', matTag, Kmax, Kur, Rf, Fult, gap)

This command is used to construct a hyperbolic gap material object.

matTag (int) integer tag identifying material
Kmax (float) initial stiffness
Kur (float) unloading/reloading stiffness
Rf (float) failure ratio
Fult (float) ultimate (maximum) passive resistance
gap (float) initial gap


  1. This material is implemented as a compression-only gap material. Fult and gap should be input as negative values.
  2. Recomended Values:
    • Kmax = 20300 kN/m of abutment width
    • Kcur = Kmax
    • Rf = 0.7
    • Fult = -326 kN per meter of abutment width
    • gap = -2.54 cm

See also