OrcaFlex를 이용한 심해 SCR 구조 해석

Abstract

The design challenges when attempting to obtain sufficient strength for a deepwater steel catenary riser (SCR) include high stressnear the hang-off location, an elevated beam-column buckling load due to the effective compression in the touchdown zone (TDZ), and increasedstress and low-cycle fatigue damage in the TDZ. Therefore, a systematic strength analysis is required for the proper design of an SCR. However,deepwater SCR analysis is a new research area. Thus, the objective of this study was to develop an overall analysis procedure for a deepwater SCR. The structural behavior of a deepwater SCR under various environmental loading conditions was investigated, and a sensitivity analysis wasconducted with respect to various parameters such as the SCR weight, weight of the internal contents, hang-off angle (HOA), and vertical soilstiffness. Based on a deepwater SCR design example, it was found that the maximum stress of an SCR occurred at a hang-off location underparallel loading direction with respect to the riser plane, except for a wave dominant dynamic survival loading condition. Furthermore, the tensilestress governed the total stress of the SCRs, whereas the bending stress governed the total stress at the TDZ. The weight of the SCR and internalcontents affected the maximum stress of the SCR more than the HOA and vertical soil stiffness, because the weight of the SCR, including theinternal contents, was directly related to its tensile stress.