A Vessel component may be comprised of any combination of the following vessel subcomponents:
'Support' is used to model rollerbox supports. Flat, U-shaped, V-shaped and O-shaped supports may be modelled, all of which are characterised by their physical dimensions and contact stiffness. In fact, the geometry of a rollerbox support is defined in terms of a series of lengths and angles. So in addition to the standard support types mentioned, creation of an arbitrary support type is possible, having one to five sides. Several rollerbox contact modelling options are provided, ranging from relatively simple to increasingly sophisticated and realistic. In addition to the rollerbox support, a zero-gap guide is available, which simulates a fully enclosed support, essentially behaving as a continuous circular contact surface. Where supports are placed on a stinger, the relevant Support component is referenced by a Stinger component, or by a Stinger Section component, which is in turn referenced by a Stinger component. If you wish to locate supports on a vessel, the relevant Support component is referenced by a Vessel component.
'Tensioner' is used to model the presence of a tensioner. When you create a new Tensioner component, there are no mandatory inputs associated with it – you can include a tensioner in a model once it has been created. You may optionally specify a tensioner characteristic curve in the Tensioner component, in order to define the applied tension as function of tensioner payout in a dynamic analysis. This allows you to simulate tensioner dead band and tensioner on the brake. Alternatively, rather than inputting a characteristic curve, you may define a damping coefficient on the Tensioner component. This coefficient limits the velocity of tensioner payout during a dynamic analysis and it can either remain constant throughout the analysis or it can be actively adjusted by PipeLay so as to keep the applied tension within specified dead band limits. The Tensioner component is referenced in a similar manner to the Support component, via the Stinger Section, Stinger or Vessel components.
'Stinger Section' is used to model individual sections of a stinger. These individual sections may then be combined to model a complete stinger, using the Stinger component. The data you specify for a stinger section is its length and the locations of support and/or tensioners along this length. In some cases you may also have the option to input stinger geometric and hydrodynamic properties. The Stinger Section component can reference Support and Tensioner components.
'Stinger' allows the specification of a stinger whose configurations can be of three types – Rigid S-Lay stingers, Articulated S-Lay stingers, and J-Lay towers. Rigid S-Lay stingers are further classified as being Explicitly Defined, Radius of Curvature Defined or Hinged. The Rigid S-Lay stinger and the J-Lay tower are fundamentally different to the Articulated S-Lay stinger in the following respect. The motions of the first two are completely defined by the motions of the vessel to which they are attached. In fact for these structures the stinger itself is not part of the model; only the supports on the stinger are explicitly modelled. An articulated stinger on the other hand is one that is explicitly included in the finite element model, and the motions of the stinger and any supports on the stinger are not imposed, but are in fact solved for based on the forces on the stinger, including the loading from the pipeline itself.