Node property reference¶

Axis¶

Axis

Axes are the main building blocks of the geometry. They have a position and an rotation in space. Other nodes can be placed on them. Axes can be nested by parent/child relationships meaning that an axis can be placed on an other axis. The possible movements of an axis can be controlled in each degree of freedom using the “fixed” property.

Axes are also the main building block of inertia. Dynamics are controlled using the inertia properties of an axis: inertia [mT], inertia_position[m,m,m] and inertia_radii [m,m,m]

Notes:

circular references are not allowed: It is not allowed to place a on b and b on a

Property	Read-Only	Documentation
inertia		The linear inertia of the axis in [mT] Aka: “Mass” - used only for dynamics
inertia_position		The position of the center of inertia. Aka: “cog” [m,m,m] (local axis) - used only for dynamics - defined in local axis system
inertia_radii		The radii of gyration of the inertia [m,m,m] (local axis) Used to calculate the mass moments of inertia via Ixx = rxx^2 * inertia Iyy = rxx^2 * inertia Izz = rxx^2 * inertia Note that DAVE does not directly support cross terms in the interia matrix of an axis system. If you want to use cross terms then combine multiple axis system to reach the same result. This is because inertia matrices with diagonal terms can not be translated.
fixed		Determines which of the six degrees of freedom are fixed, if any. (x,y,z,rx,ry,rz). True means that that degree of freedom will not change when solving statics. False means a that is may be changed in order to find equilibrium. These are the expressed on the coordinate system of the parent (if any) or the global axis system (if no parent) See Also: set_free, set_fixed
x		The x-component of the position vector (parent axis) [m]
y		The y-component of the position vector (parent axis) [m]
z		The y-component of the position vector (parent axis) [m]
position		Position of the axis (parent axis) [m,m,m] These are the expressed on the coordinate system of the parent (if any) or the global axis system (if no parent)
rx		The x-component of the rotation vector [degrees] (parent axis)
ry		The y-component of the rotation vector [degrees] (parent axis)
rz		The z-component of the rotation vector [degrees], (parent axis)
rotation		Rotation of the axis about its origin (rx,ry,rz). Defined as a rotation about an axis where the direction of the axis is (rx,ry,rz) and the angle of rotation is
parent		Determines the parent of the axis. Should either be another axis or ‘None’ Other axis may be refered to by reference or by name (str). So the following are identical p = s.new_axis(‘parent_axis’) c = s.new_axis(‘child axis’) c.parent = p c.parent = ‘parent_axis’ To define that an axis does not have a parent use c.parent = None
gx		The x-component of the global position vector [m] (global axis )
gy		The y-component of the global position vector [m] (global axis )
gz		The z-component of the global position vector [m] (global axis )
global_position		The global position of the origin of the axis system [m,m,m] (global axis)
grx		The x-component of the global rotation vector [degrees] (global axis)
gry		The y-component of the global rotation vector [degrees] (global axis)
grz		The z-component of the global rotation vector [degrees] (global axis)
tilt_x	Read-only	Tilt percentage. This is the z-component of the unit y vector [%]. See Also: heel
heel	Read-only	Heel in degrees. SB down is positive [deg]. This is the inverse sin of the unit y vector(This is the arcsin of the tiltx) See also: tilt_x
tilt_y	Read-only	Tilt percentage. This is the z-component of the unit -x vector [%]. So a positive rotation about the y axis results in a positive tilt_y. See Also: trim
trim	Read-only	Trim in degrees. Bow-down is positive [deg]. This is the inverse sin of the unit -x vector(This is the arcsin of the tilt_y) See also: tilt_y
heading	Read-only	Direction (0..360) [deg] of the local x-axis relative to the global x axis. Measured about the global z axis heading = atan(u_y,u_x) typically: heading 0 –> local axis align with global axis heading 90 –> local x-axis in direction of global y axis See also: heading_compass
heading_compass	Read-only	The heading (0..360)[deg] assuming that the global y-axis is North and global x-axis is East and rotation accoring compass definition
global_rotation		Rotation [deg,deg,deg] (global axis)
global_transform	Read-only	Read-only: The global transform of the axis system [matrix]
connection_force	Read-only	The forces and moments that this axis applies on its parent at the origin of this axis system. [kN, kN, kN, kNm, kNm, kNm] (Parent axis) If this axis would be connected to a point on its parent, and that point would be located at the location of the origin of this axis system then the connection force equals the force and moment applied on that point. Example: parent axis with name A this axis with name B this axis is located on A at position (10,0,0) there is a Point at the center of this axis system. A force with Fz = -10 acts on the Point. The connection_force is (-10,0,0,0,0,0) This is the force and moment as applied on A at point (10,0,0)
connection_force_x	Read-only	The x-component of the connection-force vector [kN] (Parent axis)
connection_force_y	Read-only	The y-component of the connection-force vector [kN] (Parent axis)
connection_force_z	Read-only	The z-component of the connection-force vector [kN] (Parent axis)
connection_moment_x	Read-only	The mx-component of the connection-force vector [kNm] (Parent axis)
connection_moment_y	Read-only	The my-component of the connection-force vector [kNm] (Parent axis)
connection_moment_z	Read-only	The mx-component of the connection-force vector [kNm] (Parent axis)
applied_force	Read-only	The force and moment that is applied on origin of this axis [kN, kN, kN, kNm, kNm, kNm] (Global axis)
ux	Read-only	The unit x axis [m,m,m] (Global axis)
uy	Read-only	The unit y axis [m,m,m] (Global axis)
uz	Read-only	The unit z axis [m,m,m] (Global axis)
equilibrium_error	Read-only	The unresolved force and moment that on this axis. Should be zero when in equilibrium (applied-force minus connection force, Parent axis)

BallastSystem¶

A BallastSystem

The position of the axis system is the reference position for the tanks.

Tanks can be added using new_tank()

technical notes:

System is similar to the setup of RigidBody, but without the Axis
The class extends Poi, but overrides some of its properties
Update nees to be called to update the weight and cog

Property	Read-Only	Documentation
parent		Determines the parent of the node. Should be an axis or None
position		Position of the origin of the ballast system. (Parent axis) [m,m,m]
name
cogx	Read-only	X position of combined CoG of all tank contents in the ballast-system. (local coordinate) [m]
cogy	Read-only	Y position of combined CoG of all tank contents in the ballast-system. (local coordinate) [m]
cogz	Read-only	Z position of combined CoG of all tank contents in the ballast-system. (local coordinate) [m]
cog	Read-only	Combined CoG of all tank contents in the ballast-system. (local coordinate) [m,m,m]
weight	Read-only	Total weight of all tank fillings in the ballast system [mT]

Buoyancy¶

Buoyancy provides a buoyancy force based on a buoyancy mesh. The mesh is triangulated and chopped at the instantaneous flat water surface. Buoyancy is applied as an upwards force that the center of buoyancy. The calculation of buoyancy is as accurate as the provided geometry.

There as no restrictions to the size or aspect ratio of the panels. It is excellent to model as box using 6 faces. Using smaller panels has a negative effect on performance.

The normals of the panels should point towards to water.

Property	Read-Only	Documentation
trimesh	Read-only
cob	Read-only	GLOBAL position of the center of buoyancy [m,m,m] (global axis)
cob_local	Read-only	Position of the center of buoyancy [m,m,m] (local axis)
displacement	Read-only	Displaced volume of fluid [m^3]
density		Density of surrounding fluid [mT/m3]. Typical values: Seawater = 1.025, fresh water = 1.00

Cable¶

A Cable represents a linear elastic wire running from a Poi or sheave to another Poi of sheave.

A cable has a un-stretched length [length] and a stiffness [EA] and may have a diameter [m]. The tension in the cable is calculated.

Intermediate pois or sheaves may be added.

Pois are considered as sheaves with a zero diameter.
Sheaves are considered sheaves with the given geometry. If defined then the diameter of the cable is considered when calculating the geometry. The cable runs over the sheave in the positive direction (right hand rule) as defined by the axis of the sheave.

For cables running over a sheave the friction in sideways direction is considered to be infinite. The geometry is calculated such that the cable section between sheaves is perpendicular to the vector from the axis of the sheave to the point where the cable leaves the sheave.

This assumption results in undefined behaviour when the axis of the sheave is parallel to the cable direction.

Notes: If pois or sheaves on a cable come too close together (<1mm) then they will be pushed away from eachother. This prevents the unwanted situation where multiple pois end up at the same location. In that case it can not be determined which amount of force should be applied to each of the pois.

Property	Read-Only	Documentation
tension	Read-only	Tension in the cable [kN]
stretch	Read-only	Stretch of the cable [m] Tension [kN] = EA [kN] * stretch [m] / length [m]
length		Length of the cable when in rest [m] Tension [kN] = EA [kN] * stretch [m] / length [m]
EA		Stiffness of the cable [kN] Tension [kN] = EA [kN] * stretch [m] / length [m]
diameter		Diameter of the cable. Used when a cable runs over a circle. [m]
connections		List or Tuple of nodes that this cable is connected to. Nodes may be passed by name (string) or by reference. Example: p1 = s.new_point(‘point 1’) p2 = s.new_point(‘point 2’, position = (0,0,10) p3 = s.new_point(‘point 3’, position = (10,0,10) c1 = s.new_circle(‘circle 1’,parent = p3, axis = (0,1,0), radius = 1) c = s.new_cable(“cable_1”, endA=”Point”, endB = “Circle”, length = 1.2, EA = 10000) c.connections = (‘point 1’, ‘point 2’, ‘point 3’) # or c.connections = (p1, p2,p3) # or c.connections = [p1, ‘point 2’, p3] # all the same Notes: 1. Circles can not be used as endpoins. If one of the endpoints is a Circle then the Point that that circle is located on is used instead. 2. Points should not be repeated directly. The following will fail: c.connections = (‘point 1’, ‘point 3’, ‘circle 1’) because the last point is a circle. So circle 1 will be replaced with the point that the circle is on: point 3. so this becomes (‘point 1’,’point 3’,’point 3’) this is invalid because point 3 is repeated.

Circle¶

A Circle models a circle shape based on a diameter and an axis direction

Property	Read-Only	Documentation
axis		Direction of the sheave axis (x,y,z) in parent axis system. Note: The direction of the axis is also used to determine the positive direction over the circumference of the circle. This is then used when cables run over the circle or the circle is used for geometric contacts. So if a cable runs over the circle in the wrong direction then a solution is to change the axis direction to its opposite: circle.axis =- circle.axis. (another solution in that case is to define the connections of the cable in the reverse order)
radius		Radius of the circle [m]
global_position	Read-only	Returns the global position of the center of the sheave. Note: this is the same as the global position of the parent point.

Connector2d¶

A Connector2d linear connector with acts both on linear displacement and angular displacement.

the linear stiffness is defined by k_linear and is defined over the actual shortest direction between nodeA and nodeB.
the angular stiffness is defined by k_angular and is defined over the actual smallest angle between the two systems.

Property	Read-Only	Documentation
angle	Read-only	Actual angle between nodeA and nodeB [deg] (read-only)
force	Read-only	Actual force between nodeA and nodeB [kN] (read-only)
moment	Read-only	Actual moment between nodeA and nodeB [kNm] (read-only)
axis	Read-only	Actual rotation axis between nodeA and nodeB (read-only)
ax	Read-only	X component of actual rotation axis between nodeA and nodeB (read-only)
ay	Read-only	Y component of actual rotation axis between nodeA and nodeB (read-only)
az	Read-only	Z component of actual rotation axis between nodeA and nodeB (read-only)
k_linear		Linear stiffness [kN/m]
k_angular		Angular stiffness [kNm/rad]
nodeA		Connected axis system A
nodeB		Connected axis system B

ContactBall¶

A ContactBall is a linear elastic ball which can contact with ContactMeshes.

It is modelled as a sphere around a Poi. Radius and stiffness can be controlled using radius and k.

The force is applied on the Poi and it not registered separately.

Property	Read-Only	Documentation
can_contact	Read-only	True if the ball ball is perpendicular to at least one of the faces of one of the meshes. So when contact is possible. To check if there is contact use “force” See Also: Force
contact_force	Read-only	Returns the force on the ball [kN, kN, kN] (global axis) The force is applied at the center of the ball See Also: contact_force_magnitude
contact_force_magnitude	Read-only	Returns the absolute force on the ball, if any [kN] The force is applied on the center of the ball See Also: contact_force
compression	Read-only	Returns the absolute compression of the ball, if any [m]
contactpoint	Read-only	The nearest point on the nearest mesh. Only defined
meshes		List of contact-mesh nodes. When getting this will yield a list of node references. When setting node references and node-names may be used. eg: ball.meshes = [mesh1, ‘mesh2’]
meshes_names	Read-only	List with the names of the meshes
radius		Radius of the contact-ball [m]
k		Compression stiffness of the ball in force per meter of compression [kN/m]

ContactMesh¶

A ContactMesh is a tri-mesh with an axis parent

Property	Read-Only	Documentation
trimesh	Read-only	The TriMeshSource object which can be used to change the mesh Example: s[‘Contactmesh’].trimesh.load_file(‘cube.obj’, scale = (1.0,1.0,1.0), rotation = (0.0,0.0,0.0), offset = (0.0,0.0,0.0))

CoreConnectedNode¶

ABSTRACT CLASS - Properties defined here are applicable to all derived classes Master class for all nodes with a connected eqCore element

Property	Read-Only	Documentation
name		Name of the node (str), must be unique

Force¶

A Force models a force and moment on a poi.

Both are expressed in the global axis system.

Property	Read-Only	Documentation
force		The x,y and z components of the force [kN,kN,kN] (global axis) Example s[‘wind’].force = (12,34,56)
fx		The global x-component of the force [kN] (global axis)
fy		The global y-component of the force [kN] (global axis)
fz		The global z-component of the force [kN] (global axis)
moment		The x,y and z components of the moment (kNm,kNm,kNm) in the global axis system. Example s[‘wind’].moment = (12,34,56)
mx		The global x-component of the moment [kNm] (global axis)
my		The global y-component of the moment [kNm] (global axis)
mz		The global z-component of the moment [kNm] (global axis)

GeometricContact¶

GeometricContact

A GeometricContact can be used to construct geometric connections between circular members:

steel bars and holes, such as a shackle pin in a padeye (pin-hole)
steel bars and steel bars, such as a shackle-shackle connection

Situation before creation of geometric contact:

Axis1 Point1 Circle1 Axis2 Point2 Circle2

Create a geometric contact with Circle1 and parent and Circle2 as child

Axis1 Point1 : observed, referenced as parent_circle_parent Circle1 : observed, referenced as parent_circle

_axis_on_parent                 : managed
	_pin_hole_connection        : managed
		_connection_axial_rotation : managed
			_axis_on_child      : managed
				Axis2           : managed    , referenced as child_circle_parent_parent
					Point2      : observed   , referenced as child_circle_parent
						Circle2 : observed   , referenced as child_circle

Property	Read-Only	Documentation
child		The Circle that is connected to the GeometricContact [Node] See Also: parent
parent		The Circle that the GeometricConnection is connected to [Node] See Also: child
swivel		Swivel angle between parent and child objects [degrees]
swivel_fixed		Allow parent and child to swivel relative to eachother [boolean]
rotation_on_parent		Angle between the line connecting the centers of the circles and the axis system of the parent node [degrees]
fixed_to_parent		Allow rotation around parent [boolean] see also: rotation_on_parent
child_rotation		Angle between the line connecting the centers of the circles and the axis system of the child node [degrees]
child_fixed		Allow rotation of child relative to connection, see also: child_rotation [boolean]
inside		Type of connection: True means child circle is inside parent circle, False means the child circle is outside but the circumferences contact [boolean]

HydSpring¶

A HydSpring models a linearized hydrostatic spring.

The cob (center of buoyancy) is defined in the parent axis system. All other properties are defined relative to the cob.

Property	Read-Only	Documentation
cob		Center of buoyancy in parent axis system (m,m,m)
BMT		Vertical distance between cob and metacenter for roll [m]
BML		Vertical distance between cob and metacenter for pitch [m]
COFX		Horizontal x-position Center of Floatation (center of waterplane area), relative to cob [m]
COFY		Horizontal y-position Center of Floatation (center of waterplane area), relative to cob [m]
kHeave		Heave stiffness [kN/m]
waterline		Waterline-elevation relative to cob for un-stretched heave-spring. Positive if cob is below the waterline (which is where is normally is) [m]
displacement_kN		Displacement when waterline is at waterline-elevation [kN]

LC6d¶

A LC6d models a Linear Connector with 6 dofs.

It connects two Axis elements with six linear springs.

The first axis system is called “main”, the second is called “secondary”. The difference is that the “main” axis system is used for the definition of the stiffness values.

The translational-springs are easy. The rotational springs may not be as intuitive. They are defined as:

rotation_x = arc-tan ( uy[0] / uy[1] )
rotation_y = arc-tan ( -ux[0] / ux[2] )
rotation_z = arc-tan ( ux[0] / ux [1] )

which works fine for small rotations and rotations about only a single axis.

Tip: It is better to use use the “fixed” property of axis systems to create joints.

Property	Read-Only	Documentation
stiffness		Stiffness of the connector: kx, ky, kz, krx, kry, krz in [kN/m and kNm/rad] (axis system of the main axis)
main		Main axis system. This axis system dictates the axis system that the stiffness is expressed in
secondary		Secondary (connected) axis system

LinearBeam¶

A LinearBeam models a FEM-like linear beam element.

A LinearBeam node connects two Axis elements with six linear springs.

By definition the beam runs in the X-direction of the nodeA axis system. So it may be needed to create a dedicated Axis element for the beam to control the orientation.

The beam is defined using the following properties:

EIy - bending stiffness about y-axis
EIz - bending stiffness about z-axis
GIp - torsional stiffness about x-axis
EA - axis stiffness in x-direction
L - the un-stretched length of the beam
mass - mass of the beam in [mT]

The beam element is in rest if the nodeB axis system

has the same global orientation as the nodeA system
is at global position equal to the global position of local point (L,0,0) of the nodeA axis. (aka: the end of the beam)

The scene.new_linearbeam automatically creates a dedicated axis system for each end of the beam. The orientation of this axis-system is determined as follows:

First the direction from nodeA to nodeB is determined: D The axis of rotation is the cross-product of the unit x-axis and D AXIS = ux x D The angle of rotation is the angle between the nodeA x-axis and D

The rotation about the rotated X-axis is undefined.

Property	Read-Only	Documentation
EIy		E * Iyy : bending stiffness in the XZ plane [kN m2] E is the modulus of elasticity; for steel 190-210 GPa (10^6 kN/m2) Iyy is the cross section moment of inertia [m4]
EIz		E * Izz : bending stiffness in the XY plane [kN m2] E is the modulus of elasticity; for steel 190-210 GPa (10^6 kN/m2) Iyy is the cross section moment of inertia [m4]
GIp		G * Ipp : torsional stiffness about the X (length) axis [kN m2] G is the shear-modulus of elasticity; for steel 75-80 GPa (10^6 kN/m2) Ip is the cross section polar moment of inertia [m4]
EA		E * A : stiffness in the length direction [kN] E is the modulus of elasticity; for steel 190-210 GPa (10^6 kN/m2) A is the cross-section area in [m2]
mass		Mass of the beam in [mT]
L		Length of the beam in unloaded condition [m]
nodeA		The axis system that the A-end of the beam is connected to. The beam leaves this axis system along the X-axis
nodeB		The axis system that the B-end of the beam is connected to. The beam arrives at this axis system along the X-axis
moment_A	Read-only	Moment on beam at node A (kNm, kNm, kNm) , axis system of node A
moment_B	Read-only	Moment on beam at node B (kNm, kNm, kNm) , axis system of node B
tension	Read-only	Tension in the beam [kN], negative for compression
torsion	Read-only	Torsion moment [kNm]. Positive if end B has a positive rotation about the x-axis of end A
torsion_angle	Read-only	Torsion angle [deg]. Positive if end B has a positive rotation about the x-axis of end A

Manager¶

Property	Read-Only	Documentation

Node¶

ABSTRACT CLASS - Properties defined here are applicable to all derived classes Master class for all nodes

Property	Read-Only	Documentation
visible
manager
name		Name of the node (str), must be unique

NodeWithParent¶

NodeWithParent

Do not use this class directly. This is a base-class for all nodes that have a “parent” property.

Property	Read-Only	Documentation
parent_for_export	Read-only
parent		Determines the parent of the node. Should be an axis or None

Path¶

PurePath subclass that can make system calls.

Path represents a filesystem path but unlike PurePath, also offers methods to do system calls on path objects. Depending on your system, instantiating a Path will return either a PosixPath or a WindowsPath object. You can also instantiate a PosixPath or WindowsPath directly, but cannot instantiate a WindowsPath on a POSIX system or vice versa.

Property	Read-Only	Documentation

Point¶

A location on an axis

Property	Read-Only	Documentation
x		x component of local position [m] (parent axis)
y		y component of local position [m] (parent axis)
z		z component of local position [m] (parent axis)
position		Local position [m,m,m] (parent axis)
applied_force_and_moment_global	Read-only	Applied force and moment on this point [kN, kN, kN, kNm, kNm, kNm] (Global axis)
gx		x component of position [m] (global axis)
gy		y component of position [m] (global axis)
gz		z component of position [m] (global axis)
global_position		Global position [m,m,m] (global axis)

RigidBody¶

A Rigid body, internally composed of an axis, a point (cog) and a force (gravity)

Property	Read-Only	Documentation
name
cogx		x-component of cog position [m] (local axis)
cogy		y-component of cog position [m] (local axis)
cogz		z-component of cog position [m] (local axis)
cog		Center of Gravity position [m,m,m] (local axis)
mass		Static mass of the body [mT] See Also: inertia

Scene¶

A Scene is the nodeA component of DAVE.

It provides a world to place nodes (elements) in. It interfaces with the equilibrium core for all calculations.

By convention a Scene element is created with the name s, but create as many scenes as you want.

Examples:

s = Scene()
s.new_axis('my_axis', position = (0,0,1))

a = Scene() # another world
a.new_point('a point')

Property	Read-Only	Documentation

Shackle¶

Green-Pin Heavy Duty Bow Shackle BN

visual from: https://www.traceparts.com/en/product/green-pinr-p-6036-green-pinr-heavy-duty-bow-shackle-bn-hdgphm0800-mm?CatalogPath=TRACEPARTS%3ATP04001002006&Product=10-04072013-086517&PartNumber=HDGPHM0800
details from: https://www.greenpin.com/sites/default/files/2019-04/brochure-april-2019.pdf

wll a b c d e f g h i j k weight
[t] [mm]  [kg]
95 95 208 95 147 400 238 647 453 428 50 110
105 108 238 105 169 410 275 688 496 485 50 160
120 130 279 120 179 513 290 838 564 530 70 235
130 140 299 130 205 554 305 904 614 565 70 295
140 150 325 140 205 618 305 996 644 585 80 368
170 175 376 164 231 668 325 1114 690 665 70 560
180 185 398 164 256 718 350 1190 720 710 70 685
200 205 444 189 282 718 375 1243 810 775 70 880
210 215 454 204 308 718 400 1263 870 820 70 980
210 220 464 204 308 718 400 1270 870 820 70 1100
220 230 485 215 328 718 420 1296 920 860 70 1280
240 240 515 215 349 718 420 1336 940 900 70 1460
260 270 585 230 369 768 450 1456 1025 970 70 1990
280 290 625 230 369 818 450 1556 1025 1010 70 2400

Returns:

Property	Read-Only	Documentation
kind		Type of shackle, for example GP800 [text]

Sling¶

A Sling is a single wire with an eye on each end. The eyes are created by splicing the end of the sling back into the itself.

The geometry of a sling is defined as follows:

diameter : diameter of the wire LeyeA, LeyeB : inside lengths of the eyes LsplicaA, LspliceB : the length of the splices Total : the distance between the insides of ends of the eyes A and B when pulled straight.

Stiffness: The stiffness of the sling is specified by a single value: EA This determines the stiffnesses of the individual parts as follows: Wire in the eyes: EA Splices: Infinity (rigid) Main part: determined such that total stiffness (k) of the sling is EA/L

Eye A Splice A nodeA part Splice B Eye B

/—————\ /————— | =============————————————-=============== | —————/ —————/

Tank¶

Tank provides a fillable tank based on a mesh. The mesh is triangulated and chopped at the instantaneous flat fluid surface. Gravity is applied as an downwards force that the center of fluid. The calculation of fluid volume and center is as accurate as the provided geometry.

There as no restrictions to the size or aspect ratio of the panels. It is excellent to model as box using 6 faces. Using smaller panels has a negative effect on performance.

The normals of the panels should point away from the fluid. This means that the same basic shapes can be used for both buoyancy and tanks.

Property	Read-Only	Documentation
trimesh	Read-only
cog	Read-only	Returns the GLOBAL position of the center of volume / gravity
cog_local	Read-only	Returns the local position of the center of gravity
fill_pct		Amount of volume in tank as percentage of capacity [%]
level_global		The fluid plane elevation in the global axis system. Setting this adjusts the volume
volume		The volume of fluid in the tank in m3. Setting this adjusts the fluid level
density		Density of the fluid in the tank in mT/m3
capacity	Read-only	Returns the capacity of the tank in m3. This is calculated from the defined geometry.

TriMeshSource¶

TriMesh

A TriMesh node contains triangular mesh which can be used for buoyancy or contact

Property	Read-Only	Documentation

Visual¶

Visual

.. image:: ./images/visual.png

A Visual node contains a 3d visual, typically obtained from a .obj file. A visual node can be placed on an axis-type node.

It is used for visualization. It does not affect the forces, dynamics or statics.

The visual can be given an offset, rotation and scale. These are applied in the following order

rotate
scale
offset

Hint: To scale before rotation place the visual on a dedicated axis and rotate that axis.

Property	Read-Only	Documentation

WaveInteraction1¶

WaveInteraction

Wave-interaction-1 couples a first-order hydrodynamic database to an axis.

This adds:

wave-forces
damping
added mass

The data is provided by a Hyddb1 object which is defined in the MaFreDo package. The contents are not embedded but are to be provided separately in a file. This node contains only the file-name.

Property	Read-Only	Documentation

Process finished with exit code 0

Property	Read-Only	Documentation
length		Total length measured between the INSIDE of the eyes of the sling is pulled straight. [m]
LeyeA		Total length inside eye A if stretched flat [m]
LeyeB		Total length inside eye B if stretched flat [m]
LspliceA		Length of the splice at end A [m]
LspliceB		Length of the splice at end B [m]
diameter		Diameter of the sling (except the splices) [m]
EA		Effective mean EA of the sling when eyes are flat [kN]. This is the EA that would be obtained when measuring the stiffness of the sling by putting zero-diameter pins in the eyes and stretching the sling and then using the length between the insides of the eyes.
mass		Mass and weight of the sling. This mass is discretized distributed over the two splices [mT]
endA		End A [circle or point node]
endB		End B [circle or point node]
sheaves		List of sheaves (circles, points) that the sling runs over bewteen the two ends. May be provided as list of nodes or node-names.