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Chapter 3

BucklingKollapse of Deepwater Metallic Pipes

3.1 General

Buckling and collapse strength of metallic pipes have been an important subject for the design
of pipelines, risers and TLP tendons, as well as piping, pressure vessels, tubular structures in
offshore and civil engineering.

Elastic-plastic buckling of pipes under external pressure was solved by Timoshenko as
described in his book “Theory of Elastic Stability” Timoshenko and Gere (1961). In recent
years, non-linear finite element analysis has been used as an accurate tool to predict
bucklingkollapse capacity of pipes under external pressure, bending and axial force. The
finite element model has been validated against laboratory tests and applied to derive design
equations. The review of the historic work and the latest research results on this topic may be
found from Murphey and Langner (1985), Ellinas et al. (1986), Gresnigt (1986) and a series
of journal papers by Bai et al. (1993, 1994, 1995, and 1997), Mohareb et al. (1994), Hauch
and Bai (1999,2000) and Bai et al. (1999).

NOMENCLATURE:
A Area
D Average diameter
d Depth of defect/corrosion
E Young’s modulus
F True longitudinal force
F? True longitudinal yield force
fo Initial out-of-roundness

h Thickness of defect wall
I Moment of inertia
Ki Constants
M Moment
Me Moment capacity
P Pressure