Question:

Damage Cnter module generates two sets of Href. One is "Foundation Linearization" and the other one is called Href for "Most Probable Maximum Wave". Can you please confirm what is the difference between these two Href? 

Answer:

There are two ways to calculate the effective wave height and corresponding period:

1. Foundation linearization method (using DNV-C203) where a simplified fatigue analysis (Chapter 5) is used to calculate the effective Heff and Teff values. You need to know that to get to this simplified relationship, an assumption of a = 1.8 needs to be made. The 'm' parameter is the inverse slope of the S-N curve.

2. Most probable maximum wave (ISO 19902) where the coefficient of 1.86 used for calculation of Href is based on the assumption that the typical wave period is 10 [s], which means that about 1000 waves will pass the design location in 3 hours of sea states. Refer to ISO19902 for further explanations.

 

See also: Center of Damage utility report