Elastic Contact Surface

Elastic contact surface enables the user to model contact effects between lines.

The main intention of this component is to enable modeling of pipelines during laying operations. This includes

Contact forces between the pipe and rollers on the lay barge/stinger and applied tension from a tensioner.
Contact between roller and pipe is modeled by a bi-linear or non-linear spring and a bi-linear dash pot damper.

The contact force acts normal to the pipe and the roller. It is treated as a discrete element load acting on the pipe, while the contact load acting on the roller is transferred as a nodal force to the stinger. The latter includes possible torsional moment. The term contact surface is introduced to cover stinger modeling.

The stinger may be fixed or hinged to the vessel. Generally it is curved and may consist of a rigid part following the vessel motions and a flexible part.

The term contact point is defined as the location of rollers or tensioner on the stinger.

Figure 1. Elastic contact surface

1. Setting up Elastic Contact Surface

Define components — create the contact-related components first:
- Roller Contact type (spring/damper properties)
- Tensioner type (if applicable)
- Tubular Contact type (if applicable)
Define the elastic contact surface
1. For each surface, define:
  - A set of : Contact point locations
    
    Line name, segment number, segment end, and which roller/tensioner/tubular type applies
2. Lines to be checked for contact against this elastic surface
  - Number of contact points and lines to check by specifying
    
    Line name, the first contact segment and element, the last contact segment and element.
Activate in loading sequence:
- Roller and tubular contact: activated by Roller contact forces command in Static Loading Sequence
- Tensioner: activated by Tension contact forces command in Static Loading Sequence

2. Example

See Help → Examples → Riflex → Complex Flexible Riser