Super node

Super nodes are placed at each end of the line.

Loads, specified displacements, connection to support vessel and other boundary conditions may be applied at super nodes.

Several lines may also be connected at the same super node.

1. Nodal Constraints

Options:

  1. Free

  2. Fixed or Prescribed

  3. Slave

Reference frame: Specify a reference frame for the nodal coordinate specification.

By default GLOBAL coordinate system is used as default reference frame.

1.1. Free

1.1.1. Initial position

Options:

  1. Automatic initial position : Global position is found automatically by specifying two radial reference nodes, radial distance , vertical offset amd a radial angle

  2. Global positions : Is specified by coordinates (Xg, Yg, Zg)

1.2. Fixed or Prescribed

1.2.1. Initial position

Options:

  1. Automatic initial position : Global position is found automatically by specifying a reference line and direction w.r.t. the horizontal plane

  2. Global positions : Is specified by coordinates (Xg, Yg, Zg)

1.2.2. Fixed or Prescribed configuration

  • Support vessel : Prescribed motion by specifying a support vessel. The motion is given by a RAO or by time series.

  • Static global position : X, Y and Z position of vessel coordinate system referred in global system

  • Specify the rotation of the node:

    • Direction is the rotation in degrees from global X-axis to XREF-axis and Rotation

    • Rotation is the specified rotation in degrees from stress free position to equilibrium position

Boundary conditions

  • Specification of the boundary condition frame:

    • Options

      • Global system

      • Vessel coordinate system

      • Skew global coordinate system

      • Skew vessel coordinate system

        • If Skew coordinate system is specified, the system must be defined by specifying the x-axis in the skew system [Xx,Xy,Xz] and a reference vector [Xp,Yp,Zp].

  • Specification of the boundary condition for the node : Options are free/fixed for all degree of freedoms

1.3. Slave

  • Specify the master node

1.3.1. Initial position

Options:

  1. Automatic initial position : Global position is found automatically by specifying two radial reference nodes, radial distance , vertical offset amd a radial angle

  2. Global positions : Is specified by coordinates (Xg, Yg, Zg)