|
Supports: Data |
|
|
Supports: Data |
Supports are sets of cylinders which are rigidly fixed to either a vessel or a 6D buoy, and which contact with and support specified lines. We refer to the vessel or 6D buoy as the owner of the support. The functionality of supports is identical for both types of owner.
The supports data are defined on the supports page of the owner's data form. If the geometry specification is set to explicit, then additional data are required, specified on the support coordinates page. The supports data are primarily used to identify which support types are to be used and to define the geometry of the support arrangement, e.g. where the rollers boxes are on a stinger.
The set of lines that the supports will interact with.
The supports can be released at the start of a given stage of the simulation, by setting this number to the stage number required. Once released, the supports are no longer active in the model and apply no forces or moments to supported lines. If no release is required, then set this item to '~'.
There are two different ways in which the supports geometry may be defined:
The support geometry table button reports the positions and orientations of the owner's supports. For the simple geometry specification, the data are reported relative to both the owner axes and to the support path origin axes; for the explicit geometry specification, the data are reported relative to the owner axes only.
The support path origin position defines the position of the support path origin relative to the owner's origin and with respect to the owner axes. The support path origin orientation defines the support path origin orientation with respect to the owner axes. The orientation is defined by the azimuth and declination of the support path origin $z$-axis with respect to the owner axes, and the gamma angle, which defines a rotation of the support path origin axes about its $z$-axis. At the support path origin the support path is directed along the support path origin $x$-axis.
This table defines the geometry of the support path. Each row of the table defines an individual support path section in terms of its length and bend radius. A bend radius value of infinity represents a straight path section. A positive value of bend radius can be used to curve the support path clockwise about the support path origin y-axis. A negative bend radius will instead curve the support path anticlockwise about this same y-axis.
The supports table is a numbered list of the supports, giving for each one the support type and position relative to the support path.
The arc length is the support position along the support path measured from the support path origin. For a negative arc length, the support path is linearly extrapolated in the direction of the negative support path origin $x$-axis, i.e. the support path is considered to be straight before the support path origin. Similarly, for an arc length greater than the total length of the support path, the support path is considered to be straight beyond the end of the path and is linearly extrapolated in the direction the path takes at the total length. The z offset is the offset of the support position from the support path in the support path z-axis direction (i.e. normal to the support path) at the support's given arc length.
If draw support path is selected, the support path will be drawn in the wire frame drawing using the given pen data. If not selected, the support path will not be drawn and the pen will not be available. The support path is never drawn in shaded graphics.
This table defines the positions and orientations of coordinate systems which are used when specifying the positions and orientations of supports. Name is used to refer to the coordinate system. Position defines the position of the coordinate system relative to the owner's origin and with respect to the owner axes. Orientation defines the orientation of the coordinate system with respect to the owner axes, in terms of the azimuth and declination of the coordinate system $z$-axis with respect to the owner axes, and the gamma angle, which defines a rotation of the coordinate system axes about its $z$-axis.
The support types and positions and orientations of the individual, numbered supports. Each row of the table defines an individual support. A coordinate system, relative to which the support coordinate position and orientation are defined, must be specified. Position defines the position of the support relative to the coordinate system position and with respect to the coordinate system axes. Orientation defines the orientation of the support axes with respect to the coordinate system axes, in terms of the azimuth and declination of the support $z$-axis with respect to the coordinate system, and the gamma angle, which defines a rotation of the support axes about its $z$-axis.