ssc-367 - Ship Structure Committee

classified as a K joint. If the load is transferred by some
combinationof shear through the joint and brace-to-brace,then the
joint is classified as a KT joint.
If the load is transferredthrough one side of the chord to another,
then the joint is classified as an Xjoint. Figure 5-9 shows joint
classification by load distribution.
5.4.3
Empirical Eauations
Prior to the discussion of empirical equations it is beneficial to
briefly discuss the available data on SCFS. Review of various
publisheddata (References1.8, 5.19, 5.20, 5.21 and 5.22) indicate
that substantial scatter of SCFS is observed. Variations in SCFS
occur in both nominally identical joints and in symmetrical
locations of joints where one would expect little variations in
SCFS. Material and fabrication imperfectionscontribute to the SCF
variations. Lalani et al (Reference 5.23) point out that the
parameterscontributingto these variationscan be grouped intotwo:
●
Experimental error, including modeling, gauge position and
measurements and the loading.
●
Expected variations due to material and fabrication
imperfections,includingvariations in weld profile, size and
imperfections.
The use of empirical formulationshas been extensively accepted for
fatigue analysisof marine structures. A set of empirical formulae
developed by Kuang (Reference 3.2) were derived by evaluating
extensive thin-shellFEA results. The formulae proposed by Smedley
(Reference3.3) and Wordsworth (Reference3.4) of Lloyd’s Registry
were derived from evaluating the results of strain-gauged acrylic
models. Other empirical equations published include those by
Gibstein (References 5.21, 5.24), Efthymiou (5.19) and Wordsworth
(5.25).
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