Slender System Connection

This option enables the user to make a coupled model, i.e. simultaneous analysis of vessel motions and mooring/riser dynamics. The vessel load model may account for wind, wave and current forces, which are applied as nodal loads. For further description of vessel load model, confer SIMO user manual.

In a coupled model, a body node is added for each body in the system. This node may have a rigid connection to a slender system node or may be a free or fixed node not automatically connection to the slender system.

The available connection options are:

  • Element: The body node is a slave of a node specified by line, segment, element and end node

  • Node: The body node is a slave of a node specified by line, segment and node

  • Supernode: The body node is a slave of supernode. A dummy line will be created automatically if the supernode is not attached to a line.

  • Position: The body node is a free or fixed node that is not attached to the slender system. A connection may be made by making a supernode in the slender system a slave of the body node or by using a boundary change in static or dynamic analysis.

In addition, an artificial stiffness may be given for each body. This is only applied in static analysis. This may be used to improve convergence and limit displacements in static analysis, typically for very soft modes like rotation of a turret.

Boundary change in static or dynamic analysis is often a better alternative than using articial stiffness.
This option requires licenses to both RIFLEX and SIMO.