Page 218 - Marine Structural Design

194 Part II Ultimate Strength

0.8

0.6

0.4

0.2

0
0.2 0.4 0.6 0.0 1.0
WMp

(a) e/O = 1/8 (b) e/O 1/4
1 .o
P/Pp
0.8

9.6 n : PARAMETER TO OETERnINE'8ENDING
MOMENT
ISUM
---
0.4 A:
: .FEM
------ : EXPERIMENT
0.2 0 : ONSET OF
LOCAL BUCKLING
IN EXPERIMENT
0 0.2 0.4 0.6 0.0 1.0
M/ Mp

(c) e/O = 3/8

Figure 9.29 Measured and Calculated Relationship Between Axial Force
and Bending Moment

If pure bending is obtained, the axial force is zero and the proposed method does not need to
be applied. In this case, the filly plastic condition will give an accurate ultimate strength.
Furthermore, this method is not necessary when the axial force is in tension.

9.5 Conclusions
Local buckling of tubular members is investigated in this chapter both theoretically and
experimentally. First, a series of experiments are carried out on large and small-scale tubular
specimens. Large-scale test specimens are 1/33 scale model of a bracing member in an