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*Properties |
 
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*Properties
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*Properties |
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To assign effective structural properties to hot spot sets for use in calculating stresses.
Refer to Stress Properties for further information on this feature.
A block of two lines repeated as often as necessary. Each property specified on the second line can be omitted, in which case a default value will be used for stress calculations:
SET=Set Name
Do, Di, A, Iyy, Izz
The properties specified here are used in calculating stresses during fatigue analysis. This keyword is optional and may be ignored if you wish to use the actual properties (e.g. via the *GEOMETRIC SETS keyword in $MODEL ), or properties explicitly specified for stress computations (i.e. via the corresponding *PROPERTIES keyword in $MODEL), as the values specified in the model definition are carried through to LifeFrequency.
If any of the parameters A, Iyy or Izz are omitted, default values are computed based on the specified (or default) values of Do and Di.
Input: |
Description |
Set Name: |
The name of the element set to which the stress properties are to be assigned. This defaults to all elements. |
Do: |
The effective outside diameter for the elements of the set. The default depends on the format used to specify geometric data. If you used the Flexible Riser format, then the default is the drag diameter for the elements of the set. If you used the Rigid Riser or Mooring Line formats, then Do here defaults to Do input in the properties data. |
Di: |
The effective internal diameter for the elements of the set. The default is the internal diameter specified in the geometric data. |
A: |
The effective cross-sectional area for the elements of the set. The default is given by:
where Do and Di are the inputs described above, default or otherwise. |
Iyy: |
The second moment of area about the local y-axis for the elements of the set. The default is given by:
where Do and Di are the inputs described above, default or otherwise. |
Izz: |
The second moment of area about the local z axis for the elements of the set. The default is Iyy above. |
(a)This table is identical to the Properties – Stress table of the main $MODEL section. If you use the table in $MODEL to specify stress properties, then these automatically carry through to LifeFrequency and you do not need to repeat the specification here. Refer to Stress Properties for a detailed discussion of the various parameters above.
(b)LifeFrequency reads stress properties from the output files produced by the first Flexcom analysis in your Pre-Run Analyses list. So if you specify stress properties in the Flexcom data for that analysis, once again you do not need to repeat them here.
