op3.anchors.cyclic_capacity_reduction

op3.anchors.cyclic_capacity_reduction(anchor: SuctionAnchor, soil: UndrainedClayProfile, *, storm_duration_hours: float = 3.0, wave_period_s: float = 10.0, tau_cyc_over_su: float = 0.5, method: Literal['andersen_2015'] = 'andersen_2015') → CyclicResult[source]

Ultimate-capacity cyclic reduction factor for a 3-hour design storm.

Parameters:

  • anchor (data model) – Anchor + soil – soil.plasticity_index drives the reduction surrogate.

  • soil (data model) – Anchor + soil – soil.plasticity_index drives the reduction surrogate.

  • storm_duration_hours (float, default 3.0) – Length of the design sea state. 3 h is the DNV standard.

  • wave_period_s (float, default 10.0) – Representative spectral peak period; the number of cycles is N = 3600 * duration / Tp.

  • tau_cyc_over_su (float, default 0.5) – Amplitude ratio of the cyclic shear stress at the anchor to the static undrained shear strength. Typical 0.3-0.7 for storm loading on suction anchors.

  • method ({'andersen_2015'}) – Cyclic-strength surrogate. Future versions may add Andersen/Lauritzsen 1988 or Germano 2022.

Return type:

CyclicResult