해양 라이져 구조물 자유경간 설계

초록

Offshore risers are common components used in offshore platforms. Being vertically located, risers are weakly exposed to environment. There are many design considerations in riser design. Among them, the vortex shedding is one of the most important factors. If a vortes xhedding occurs, it could also cause a fatigue failure. The riser span betwen clamps should be decided to avoid the vortex oscillations. The current, i.e. steady flow, is the main contribution factor in vortex generation. The cyclic load and wave, affect to riser fatigue failure. The free span lengths calculated from vortex shedding analysis are compared with those from fatigue analysis. The riser models in the study are consisted of dual pipes having inner and outer pipes. The beam element moldeling is applied to convert the dual risers to equivalent condition.