ssc-367 - Ship Structure Committee

“!M91!
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Global Configurations
A design strategy that provides a global configuration with
redundancy and minimizes both the applied loads and the
response will enhance structure fatigue life and reduce
maintenance costs.
Both continuous system and discrete system global
configurationscan be optimizedto various degrees to minimize
the effect of applied loads and the response of the structure
to these appliedloads. The dynamic response of the structure
can contributeto substantialcyclic stress (i.e. both global
and local dynamics, including vortex induced vibrations) and
should be minimized.
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Joint/Weld Details
The structuraljoint/welddetails should be developed basedon
operatingexperience,analyticalstudiesand assessmentof the
impact of actual fabricationyard work to minimize the stress
concentrations,adversefabricationeffects and stresslevels.
The joint/weld details should be designed to prevent large
stress concentrations. Review of typical joint/detail
failures and analytical parametric studies should be used to
identify both “desirable” and “undesirable”details. Review
of some of the published data on structural detail’failures
(References9.2, 9.3, 4.2 and 4.3) also illustrate that such
fatigue failures can be significantly decreased by avoiding
magnification of stress patterns on a structure detail.
Jordan and Cochran (Reference9.2) surveyed 3,307 failures in
over 50 ships and presented their findings by grouping the
structural details into 12 families The review of details
within each family (twelvefamilies: beam brackets, tripping
brackets, non-tight collars, t. ght collars, gunwale
9-5