Simplified fatigue calculations are carried out for longitudinal stiffener end connections in the midship area as part of the Condition Assessment Programme (CAP) for vessels in operation. Similar type of calculations can also be carried out for other vessels as well.
The objective of the calculations is to document the fatigue life of longitudinal members amidships. The calculations will indicate areas of concern for fatigue cracks, and give guidance for close-up inspection.
The calculation identifies longitudinal members with potential fatigue problems. By focusing the inspection on these areas, the inspection can be carried out more efficiently, and the probability of detecting damages will increase. It will also make it easier to plan the maintenance of the vessel.
Calculate expected fatigue life of longitudinal end connections at one transverse web frame and one transverse bulkhead in the midship area.
Finite element calculations are used to determine the relative deflection between web frames and the transverse bulkhead.
The calculations are carried out according to procedures for simplified fatigue specified in the DNV Classification Note 30.7 “Fatigue Assessment of Ship Structures”.