Figure 4 - Time series of the transverse displacement of a riser section located 24 above seafloor
Figure 4 presents a times series of the transverse displacement of the riser section located 24 m above seafloor. This result is interesting as it shows the model capability of representing modulated responses, which is a typical non-linear behavior of slender structures under VIV.
CONCLUSIONS
The fatigue assessment has been identified as a critical issue among the activities involved in the riser design process. The inclusion of the VIV as one of the cyclic loads that cause fatigue is mandatory, but the calculation of the total fatigue damage demands new methods and models, if VIV has to be included. The use of the Ferrari & Bearman Model, as presented in this paper, may be useful for this purpose.
Some results of the Ferrari & Bearman Model are shown for a hypothetical riser case, demonstrating that the model is promising for use in riser fatigue design. Numerical and experimental tests will continue, aiming to calibrate the model and to establish its limits of application. Among those tests, special attention is given to the comparisons of the model simulation with the data gathered in the monitoring of the SCR of P-18 platform.
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