ssc-367 - Ship Structure Committee

Whatever the basis for an empirical formula, the formula has an
applicable range of parametersand the level of conservatismvaries
not only with the formulation but also within the applicable range
of parameters. The use ofSCFs also requires judgement not only on
the applicabilityof an empirical formula but also on assessment of
implicationsof in-plane and out-of-plane loadings/stresses.
The parametricequationsdevelopedby Kuang,Smedley-Wordsworth,and
$medley consist of different relationships defined by the joint
variables D, T, d, t, L, g, and 9.
Different equations are applicable for d fferent joint types.
Presently, the joint types and the applicable equations most often
used are listed below:
Joint T.YPe
TorY
K
KT
x
Applicable Equations
Kuang, Smedley-Wordsworth,& Efthymiou
Kuang, & Smedley-Wordsworth
Smedley-Wordsworth
Smedley-Wordsworth,& $medley
The empiricalequationsgiven byUEG (Reference1.8) are based on an
extensive database and relate to Woodworth equations. Modification
of Woodworth equations and the extension of the validity ranges
allow the application of UEG equations to joints with extreme
geometries. Comparisonof variousempiricalequationsshow thatUEG
equations yield generally conservative values of SCFS and are
considered to be most reliable. On the otherhand none of the
equations appear to allow accurate determination of K-joint SCFS
subjected to axial loading.
An excellent overview and reliability assessment of SCF empirical
equations are providedby Ma et al (Reference5.20),Tolloczko et al
(Reference 5.22) and Lalani et al (Reference 5.23). Further
discussion on SCFS and the predicted chord SCF for the different
equations for T and K joints are presented in Appendix C.
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