Page 101 - Marine Structural Design

Chapter 4 Scantling of Ship's Hulls by Rules 77

Drawing

Rules formulae
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Actual scantlings Rules required
to be checked
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Figure 4.6 Data Flow in the Procedure of Structural Scantling

4.3.2 Hull Girder Strength
The structural members involved in the primary stress calculations are, in most cases, the
longitudinally continuous members, such as deck, side, bottom shell, longitudinal bulkheads,
and continuous or fully effective longitudinal stiffening members.
Most design rules control hull girder strength by specifying the minimum required section
properties of the hull girder cross-sections. The required section properties are calculated
based on hull girder loads and maximum allowable hull girder stresses for the mid-ship
parallel body (region in which the cross-sections are uniform).
Longitudinal Stress
In order to determine the hull girder section modulus for 0.4L amidships, classification rules
require that the greater value of the following equation be chosen:

SM = O.OIC,L~B(C, +0.7) (4.7)