Motions and Mooring Lines of Floaters. Lecture in TMR 4195, March 20, 2007 Sverre Haver. Floater, mooring lines and risers. z. Wind. x(t). Waves. x. Current. f(t). Risers. Mooring Lines. Anchors. Force processes. Wind (mean force and slowly varying force) Current (mean force)
Lecture in TMR 4195, March 20, 2007
Linearized transfer function
sR = response st.dev.
= no of WF cycles in3 hours
Mean load,accounted for above
Varying wind force, vw,turb isGaussian, i.e. the variable forceis Gaussian (frequency domainsolution is convenient)
Expected 3-hour maximum reads:
In this formula it is assumed that wind induced and wave inducedlow frequency 3-hour extremes are independent.
Significant response amplitude is equal to two times the standard deviation of the corresponding response component.
More accurate results requires solving the equation of motion in time domain or a large number of 3-hour model tests.