Coupled dynamic analyses of a deep-water Semi-submersible platform, in the South China Sea region, is carried out under postulated damage of the restraining system for both 10 and 100-years return period events. Under the combined action of wind, wave, and current loads, motion responses of Semi-submersible at 1500 and 2000 m water depths are analyzed in time-domain. Dynamic tension variations in the mooring lines are investigated for a fatigue failure using the S–N curve approach. Inclusion of a submerged buoy in the mooring system resulted in a marginal increase of the response due to a reduction in the restoration force of the mooring lines; submerged buoy also resulted in additional damping. The results of numerical studies showed an increase in tension in the mooring lines, which are adjacent to the damaged ones, causing reduced fatigue life. With the inclusion of submerged buoy in the mooring system, there is a considerable decrease in tension variation in mooring lines, increasing fatigue life. Failure of a mooring line causes an increase in tension of the adjacent mooring line, but not valid under all circumstances. It is seen from the studies that despite the postulated failure induced in a mooring, the adjoining line remains unaffected due to a steady coupling motion of the platform.

对南海地区深水半潜式平台进行了耦合动力分析，在假定的约束系统对10年和100年回归期事件的破坏下进行了分析。在风，浪和水流的共同作用下，对半潜水器在1500和2000 m水深处的运动响应进行了时域分析。使用S–N曲线方法研究了系泊缆绳中的动态张力变化是否导致疲劳破坏。由于系泊缆的恢复力降低，因此在系泊系统中包含浸入式浮标会导致响应略有增加。水下浮标还导致额外的阻尼。数值研究的结果表明，与受损缆绳相邻的系泊缆绳中的张力有所增加，从而导致疲劳寿命降低。系泊系统中包含浸入式浮标后，系泊索的张力变化显着降低，从而延长了疲劳寿命。系泊缆的故障会导致相邻系泊缆的张力增加，但并非在所有情况下均有效。从研究中可以看出，尽管在系泊设备中引发了假定的破坏，但由于平台的稳定耦合运动，相邻的绳索仍不受影响。