Stress Properties |
 
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Stress Properties |
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The outputs from a Flexcom analysis include bending, axial, hoop and von Mises stresses. How the program calculates these is described in detail in Force and Stress Outputs. Those calculations though use for each element the external diameter De, the internal diameter Di, the cross-section area A and the moment of inertia I. What values Flexcom selects for these is the subject of this short section.
The first point to make is that you have the option to define any or all of these so-called stress properties independently of defining geometric properties. You can define stress properties as part of your finite element model definition, or you can do so when defining data for postprocessing. (Using the parlance of keyword files, you can define stress properties either in your '$MODEL' data or in your '$DATABASE POSTPROCESSING' data.)
The following summarises what happens if you do not explicitly define any of De, Di, A or I. The program default operation depends in the case of De on whether you used the Flexible Riser Format, Rigid Riser Format or Mooring Line Format in defining geometric properties for a particular element; for the other properties it is the same regardless.
Further information on this topic is contained in the following sections:
There are several keywords which may be used to assign effective structural properties to element sets for use in calculating stresses.
•*PROPERTIES in the $MODEL section.
•*PROPERTIES in the $DATABASE POSTPROCESSING section.
•*PROPERTIES in the $LIFETIME FATIGUE section.
•*PROPERTIES in the $LIFEFREQUENCY section.