Page 177 - Marine Structural Design
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Chapter 8 Buckling/Collapse of Columns and Beam-columns 153
~CEI
PE =- (8.83)
l2
where c is the end-fixity coefficient and
Z2EI
P, =- (8.84)
where I' is the effective length.
End-Fixity Effective
Boundary Conditions Coefficient Length
1 l J C I'
P I
Pinned-Pinned: & 1 .o I
Fixed-Guided: 5 9-NX 4.0 0.51
Fixed-Pinned: & 2.05 0.71
Fixed-Free % #- & 0.25 21
Figure 8.5 End-Fixity Coefficients and Effective Length for Column
Buckling with Various Boundary Conditions
8.4.2 Example 8.2: Two Types of Ultimate Strength: Buckling vs. Fracture
Problem:
Compare type diffkrent types of ultimate strength problems in a table: buckling vs. fracture.
Solution:
Normally ultimate strength analysis is inelastic buckling analysis of beam-columns, plates and
shells with initial imperfections. However, it should be pointed out that final fracture is also
part of the ultimate strength analysis. The assessment of final fracture has been mainly based
on BPD6493 (or BS7910) in Europe and API 579 in the USA, see Chapter 21. In fact there is a
similarity between buckling strength analysis and fracture strength analysis, as compared in
the table below:
