Page 67 - Pipelines and Risers

Chapter 3

Bursting pressure
Characteristic collapse pressure
External pressure
Elastic buckling pressure
Internal pressure
Limit pressure
Plastic buckling pressure
Yield pressure
Average pipe radius of non defect pipe
Specified Minimum Tensile Strength
Specified Minimum Yield Strength
Nominal wall thickness
Deflection from circular shape at point i
Maximum initial defection from circular shape
Half of the defectkorrosion width
Anisotropy factor
Distance from axis of bending to mass center

Distance from center for moment of inertia to outer fiber of wall
Curvature
Poisson’s ratio
Hoop stress
Yield hoop stress
Limit hoop stress for pure pressure
Longitudinal stress
Yield longitudinal stress
Limit longitudinal stress for pure longitudinal force
Yield radial stress
Yield stress
Angle from bending plane to plastic neutral axis

3.2 Pipe Capacity under Single Load

3.2.1 General
The limit moment is highly dependent on the amount of longitudinal force and pressure loads
and for cases with high external pressure also initial out-of-roundness. This is mainly due to
that the deformation of the pipe caused by the additional loads either work with or against the
bending induced deformation.