Coatings |
 
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Coatings |
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Flexcom provides a facility to apply coatings on an element set basis. This feature is useful when modelling, for example, the effect of insulation or marine growth.
Multiple coatings can be applied. Each coating is characterised by its name, type (whether internal or external), thickness, mass density, and the element set to which it applies. Note that coating names are intended for descriptive purposes only and have no effect on the internal computations.
When multiple coatings are assigned, the coatings are assumed to occur in the order specified from the base section – inwards in the case of internal coatings and outwards for external coatings. Some caution is required where there is overlap between coated element sets. If an element is present in more than one coated element set, coatings from each set will be applied, and the order will be consistent with the set definitions referenced during the definition of coatings.
The application of coatings causes an increase in mass per unit length or mass density, while stiffness properties remain unchanged. The various diameters (drag, buoyancy, outer, contact and internal) are also adjusted as appropriate. Specifically, the internal diameter is reduced where one or more internal coatings are present, and the outer diameter is increased if one or more external coating is present. The remaining diameters (drag, buoyancy and contact) are only adjusted where the relevant user specified value is exceeded by the outer diameter plus any external coatings. It is important to note that the diameters used for stress computations are unaffected by the presence of coatings, and the values specified for the base section take priority.
The option to specify coatings is independent of the geometric format option used to define the base element set, whether Flexible Riser, Rigid Riser or Mooring Line. Note however that if you are using the Flexible Riser format, then the outer diameter Do (which is immaterial in the majority of cases) becomes a required input.
•*GEOMETRIC SETS is used to assign geometric properties to element sets.
•*COATINGS is used to apply coatings on the basis of element set.
If you would like to see an example of how this keyword is used in practice, refer to K02 - Worked Example - Complex.