Class notation using direct load calculations to evaluate the fatigue within the cargo area.

Purpose

To calculate the fatigue of the hull structure within the cargo area by using directly calculated hydrodynamic loads. Wave loads are calculated in a hydrodynamic program and transferred to a structural model of the entire ship.

Benefits

A CSA-FLS ship has a higher fatigue life for critical details than a normal classed ship. It will therefore be a safer ship, with a reduced likelihood of fatigue cracks. The increased fatigue strength will make it less likely that the ship will cause pollution or require repair, thus reducing the long-term cost for the owner.

Features

The notation applies direct calculations of the wave loads and finite element calculations of the total hull and extended fatigue control. The design load conditions are to include the ballast, full load and part load conditions based on the load definitions for direct strength calculations. In connection with the direct wave load calculations, it is important to note that the comparable wave loads are based on a rational combination of characteristic hull parameters, backed by long experience and checked by non-linear wave load calculations. The rule wave loads correspond to a maximum wave response
at 10-8 probability in the North Atlantic. The effect of forward speed is included in the analyses. A stochastic (spectra) fatigue analysis is performed for longitudinals/plating and other critical locations within the cargo hold area.