1. Line and segment specification
1.1. Data group identifier, one input line
Lines which represent stress joints are specified in data group Stress joint line specification.
The total number of line types and stress joints has to be less or equal to 500 in the present version.
NEW LINE DATA
1.2. Line type specification, one input line
LINTYPID NSEG NCMPTY2 FLUTYP IADDTWI IADDBEND

LINTYPID: character(8)
: Line type identifier. 
NSEG: integer
: The number of segments the line type consists of. 
NCMPTY2: character/integer, default: 0
: Reference to nodal component type,CMPTYPID
, attached to end 2 of segmentNSEG
.
Must be type
BODY
,CONB
,FLEX
orDRAG
. 
NCMPTY = 'NONE'
or'0'
means that no nodal component is attached at end 2 of segment NSEG.


FLUTYP: character/integer, default: 0
: Reference to internal fluid component type identifier. Must be of typeFLUID
.
FLUTYP = 'NONE'
or'0'
means no fluid in the line.


IADDTWI: integer, default: 0
: Indicator for twist information (Relative rotation around the line type length axis).
IADDTWI = 0
: No extra specification to be given. 
IADDTWI = 1
: Extra specification to be given.


IADDBEND: integer, default: 0
: Indicator for precurved line type, i.e. offsets transverse to the straight line between the line ends.
IADDBEND = 0
: No extra specification to be given. 
IADDBEND = 1
: Extra specification to be given at the second end of all but the last segment within the line type 
IADDBEND = 2
: Extra specification to be given at the second end of all segments

1.3. Segment specification. NSEG input lines.
CRSTYP NCMPTY1 EXWTYP NELSEG SLGTH NSTRPS NSTRPD SLGTH0

CRSTYP: character
: Reference to crosssectional component type identifierCMPTYPID

Must be of type
CRS0
…CRS7
orFIBR


NCMPTY1: character/integer, default: 0
: Reference to nodal component type identifier,CMPTYPID
, attached to end 1 of segment.
Must be type
BODY
,CONB
,FLEX
orDRAG
. 
NCMPTY1 = 'NONE'
or'0'
means that no nodal component is attached at end 1 of segment.


EXWTYP: character/integer
: Reference to external wrapping (distributed weight or buoyancy) component type identifierCMPTYPID
.
Must be of type
EXT1
. 
EXWTYP = 'NONE'
or'0'
means no external wrapping.


NELSEG: integer
: Number of elements for FEM analysis 
SLGTH: real > 0
: Segment length \(\mathrm {[L]}\) 
NSTRPS: integer, default: 3
: Number of sections each element is divided into for hydrodynamic calculation; static analysis. 
NSTRPD: integer, default: 5
: Number of sections each element is divided into for hydrodynamic load calculation; dynamic analysis. 
SLGTH0: real, default: SLGTH
: Actual stress free segment length
NSTRPS
and NSTRPD
are used only for the crosssection type CRS5
If the stress free length of the line (sum of the segment SLGTH
) is
not equal to the distance between the stress free coordinates of the
supernodes that the line is attached to, the stress free line length
will be modified according to the following rules:
Length modification will always be done on the last segment within the line. Therefore the first task is to check if it is possible to modify this segment to obtain a line length equal the to the distance. If this is not possible the program will terminate with error message. Then the difference between the length and the distance is within the preset length tolerance:  Difference larger than 1% gives error termination.  Difference between 0.1% and 1% gives modification and written warning.  Difference less than 0.1% gives modification but no warning.
Specifying SLGTH0
\(\mathrm {\neq }\) SLGTH
enables the
user to use initially stressed segments at the start of the static
analysis. This feature is useful for modelling elastic springs between
element nodes. SLGTH
will be interpreted as stressed segment length by
the program.
1.4. Relative twist specification
The following NSEG input lines is to be given if IADDTWI = 1
.
TWEND1 TWEND2

TWEND1: real
: Relative twist segment end 1 \(\mathrm {[deg]}\) 
TWEND2: real, default: TWEND1
: Relative twist segment end 2 \(\mathrm {[deg]}\)
The relative twist for elements within the segment is calculated by use of linear interpolation. The twist angle is constant over the element length. The twist angle of the actual line will relate to the line local Yaxis.
The local Yaxis may be set using the data group LOCAL ELEMENT AXIS, be determined by shaft and blade orientation for a wind turbine blade or the default procedure may be used. See Line, line type and supernode connectivity for details.
1.5. Transverse offset specification
If IADDBEND = 1
the following NSEG1 input lines are to be given.
Offsets at the last node of the last segment are set to zero.
If IADDBEND = 2
the following NSEG input lines are to be given.
DY DZ

DY: real, default: 0
: Offset in line local Yaxis segment end 2 \(\mathrm {[L]}\) 
DZ: real, default: 0
: Offset in line local Zaxis segment end 2 \(\mathrm {[L]}\)
This feature enables the user to model a curved stressfree
configuration of a line type by specifying transverse offsets at end 2
of all line segments, i.e. transverse offsets from the straight line
between the line ends. The offsets DY
and DZ
refer to the initial
local line Y and Z axes, disregarding any specified relative twist.
Note! If only NSEG1 input lines are given, the offsets are set to zero for the second end of the last segment.
Specified twist will be applied around the updated local element Xaxis after the offsets have been accounted for.
The stressfree segment lengths SLGTH
will be modified according to the
specified offsets. If a segment consist of more than one element, the
intermediate nodes will be placed along the straight line between the
segment nodes.
The crosssection properties will not be changed, e.g. the specified mass per unit length will be used together with the modified segment length.
Note! If nonzero offset is specified at the second end of the last segment, no other line may be connected to this supernode
The local Yaxis may be set using the data group LOCAL ELEMENT AXIS, be determined by shaft and blade orientation for a wind turbine blade or the default procedure may be used. See Line, line type and supernode connectivity for details.