The fatigue analysis in this example is carried out for the random sea loading corresponding to stage number 3. The figure below shows a plot of the maximum fatigue damage rate along the pipeline for the random sea loading. The maximum fatigue damage rate occurs at the tower support closest to the tensioner, which is the 1m O-Support. A lesser peak in fatigue damage rate occurs in the touchdown region.
Maximum Fatigue Damage Rate
The overall results from the fatigue analysis are summarised in the table below. The total fatigue damage sustained by a weld during the pipe laying operations is estimated at 0.38053E-04. This represents a maximum standby time of 0.32645E+04 hours, roughly 136 days, based on the maximum allowable damage of 0.1. The maximum fatigue damage rate occurring in the touchdown zone is 0.39486E-08 per second.
Table: Normal Lay Fatigue Results
Property |
Value |
Total Fatigue Damage |
0.38053E-04damage |
Maximum Standby Time |
0.32645E+04 hours |
Maximum Fatigue Damage Rate in Touchdown Region |
0.39486E-08 damage/s |