Response of steel catenary risers on hysteretic non-linear seabed

The methodologies recommended by existing codes and standards for design of steel catenary risers are considering linear springs in the seabed while it is publicly accepted that the non-linear riser-seabed interaction can have vital influence on stress variation in touchdown area and consequently fatigue performance during the cyclic motions of the riser as the latter is excited by vessel motions under environmental loads. In this study an advanced hysteretic non-linear riser-seabed interaction model has been implemented into the seabed enabling the automatic simulation of different stiffness in the seabed response through the touchdown zone and gradual embedment of riser. Then the impacts of this model on fatigue calculation procedure and fatigue performance in touchdown area has been studied. © 2014 Elsevier Ltd.