Lines |
 
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Lines |
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*LINES may be used to define a straight line or a catenary section. Several connecting catenaries, created by weight and buoyancy distributions (e.g. such as a lazy-wave catenary), may also be modelled using *LINES.
Line Paths is better suited to modelling a line with an arbitrary geometrical configuration (e.g. such as a rigid spool).
The lines modelling feature provides an automatic mesh creation facility for nodes, elements and cables. Note that ‘line’ in this context does not imply a straight line section; a catenary section is equally valid. The main aspects to creating a line are as follows:
•Associating a descriptive name with the line
•Defining start and end locations
•Specifying the line length
•Specifying line mesh generation settings
•Assigning structural and hydrodynamic properties
•Defining boundary conditions at line end points
Some advanced topics which merit further discussion also include:
•Connecting lines together
•Modelling repeating sub-sections within a single line
•Using the line facility to create pipe-in-pipe configurations
•The significance of local undeformed element axes in relation to lines
Each of these topics is discussed in further detail in the following sections.
•*LINES may be used to define a straight line or a catenary section. Several connecting catenaries, created by weight and buoyancy distributions (e.g. such as a lazy-wave catenary), may also be modelled using *LINES.
•*LINE LOCATIONS is used to define named locations along a line, allowing you to request that nodes be positioned exactly at specific lengths along a line.
•*LINE SECTION GROUPS is used to define groups of line sections which may be reused and repeated within sections defined in *LINES.
•*LINES PIP is used to specify that two lines are connected in a pipe-in-pipe (or pipe-on-pipe) configuration. *LINES PIP provides a high degree of automation in terms of setting up pipe-in-pipe configuration, but for complete generality and increased user control, the *PIP CONNECTION and *PIP SECTION keywords are recommended.
If you would like to see an example of how these keywords are used in practice, refer to Example H02 - J-Tube Pull-In.