This technical note provides a description of the procedure used by PipeLay to calculate moment-curvature (M-κ) curves for pipe elements where the mechanical behaviour of the associated pipe section material is specified by means of a stress-strain (σ-ε) curve. If desired this procedure can account for the effects of an input tension value that the pipe is likely to encounter during the installation scenario in question.

The procedure can also cater for pipe sections with external coatings where the respective coating properties have a stiffening effect on the pipe section, for example concrete coatings.

The technical note consists of the following subsections:

1.Moment-Curvature Calculation with a Tension Input

2.Moment-Curvature Calculation with External Coatings and Tension

i.Moment Curvature Calculation without Slippage

ii.Calculation of Slippage in the Outermost Coating

3.Postprocessing of Bending Moments and Stresses in the Steel Layer