Pipe Section Best Practice
1.Try to use the Standard specification as much as possible. This is the quickest and easiest way to generate pipe properties.
2.Review the calculated values in the square brackets, [ ], in particular the weight in water. This can be negative for large diameter pipes, which indicates the need for concrete coatings to make the pipe heavier.
3.Typical pipe hydrodynamic coefficient values are as follows:
a.Normal Drag: 0.7 to 1.0
b.Tangential Drag: 0.0
c.Normal Inertia: 2.0
d.Tangential Added Mass: 0.0
e.Normal Added Mass: Empty (PipeLay defaults it to Normal Inertia – 1)
4.When applying coating stiffness contributions keep the following points in mind. Also, please refer to Technical Note 7 for more details on how coating stiffness contributions are calculated by PipeLay.
a.Model the field joints with a separate pipe section.
b.No BBR (Bond Bending Resistance) input for the outermost coating results in a perfect coating bond with no slippage captured.
c.Coating density is still required even when the materials are specified.
d.Define all coatings materials using a non-linear stress-strain curve.
e.For specific advice on the calculation of BBR values and the discretisation of pipe joints with different BBR regions, please refer to the OPT Asia 2015 paper, “The Effect of Concrete Coating Stiffness on Global Pipeline Response during Installation”.