fairlead tension

[dorsamgh]

Hello, I hope you're doing well.
I have a question regarding the changes in the tension of the fairlead in the mooring line system of 15MW semi-submersible floating wind turbines. If we want to introduce a fault in this area, meaning to create some malfunction, how would the tension change?

Assuming that the fairlead is worn out and mechanically degraded, causing a reduction in its cross-sectional area, I modified the tension in the fairlead of mooring line number one as shown in the attached pic. I have two main questions:

1. Is it reasonable for the tension to increase under these conditions, or should it decrease? And is this fault justifiable in this context?
2. Is the amount of increase logical? For example, is it justifiable for the tension to increase by 10% starting from second 400? Or should the increase not be proportional or use this specific percentage?

thank you,

[shousner]

Hello,

The change in tension with a mechanically degraded mooring line will likely depend on the other properties of the mooring line, such as weight or axial stiffness. Without knowing those properties or catching up on recent published work, it is tough for me to say whether that will increase or decrease the tension. These realistic changes in line tension can likely be found by a quick literature review, depending on the amount, or style, of line degradation.

Stein

[dorsamgh]

Dear @shousner

Thank you for your response. I would like to begin by mentioning that my simulation model is a 15 MW semi submersible floating offshore wind turbine.

My intention is to introduce a fault on the fairlead of the mooring line in such a way that the performance of the wind turbine is affected, but without causing shutdown or instability. The specific fault I'm considering is related to the out-of-plane bending of the chain or wire rope / or wear of the fairlead . Essentially, I plan to examine the effect of this fault in the simulation by manipulating the tension value in segment N (fairlead) of one of the mooring lines.

I appreciate your guidance in advance.

Best regards