The project sidebar for this example is shown in the figure below. The project sidebar shows all of the components that are used in the example. Each of these components is described in detail in the following sections.
Project Sidebar for Example 6
When a new PipeLay project is created it contains just a Project component. This component is used to store general project information such as the project title, location, and so on. The Project component is also used to specify certain project-specific settings such as the system of units to be used, global constants, finite element mesh settings and quality control procedures. For this example, the following information is stored in the general Project Settings dialog.
Table: General Project Settings
Property |
Value |
Project Title |
Example 6 - Start-up via Stab & Hinge |
Job Number |
1-2-3-342 |
Engineer(s) |
Wood PLC |
Location |
Galway |
For this example, the default Metric unit system and the default Constants dialog values are used. Also, the ‘Quality Control’ section is left as per default.
The Material component is used to define the physical properties associated with a particular material. This example contains one Material component, which define the material properties for nonlinear X65 steel as listed in the first table below. The Material component is located in the Material folder and are named ‘X65 Steel’ in this example.
Table: Material Properties for ‘X65 Steel’
Property |
Value |
Young's Modulus |
207 GPa |
Shear modulus |
80 GPa |
Poisson’s Ratio |
0.3 |
Mass Density |
7850 kg/m3 |
Yield Strength |
450 MPa |
Allowable Stress |
100 % |
Allowable Strain |
0.25 % |
Expected Tension |
500 kN |
Stress-Strain Curve for ‘X65 Steel’
The Pipe Section component is used to specify the properties of an individual section of pipeline that has uniform properties. This example contains one Pipe Section component as follows:
▪The Pipe Section component is created in the Line folder and is named ‘18" Pipe’.
▪The specification is Standard.
▪The material used is ‘X65 Steel’, as defined previously.
▪The geometrical and hydrodynamic properties are listed in the table below.
Table: Properties for ‘18’’ Pipe’
Property |
Value |
Outer Diameter |
457.2 mm |
Thickness |
20 mm |
Normal Drag |
1 |
Normal Inertia |
2 |
At this stage, enough components have been defined to allow for the specification of the pipeline stack-up. The Line component added to the Line folder, named ‘Pipeline’, contains 1175 m of the Pipe Section component ‘18’’ Pipe’.
This example contains two Support components to model the supports on both the vessel and the stinger. Both Support components are created in the Stinger folder. One component is a Double V Support, named ‘V-Rollerbox’, and the other component is a Zero Gap O Support, named ‘Zero Gap Guide’. The ‘Zero Gap Guide’ component has a support length of 3 m. The properties of the ‘V-Rollerbox’ component are listed in the table below.
Table: Properties of ‘V-Rollerbox’
Property |
Value |
Support Length |
0.75 m |
Roller Length, L1 |
0 m |
Roller Length, L2 |
1.5 m |
Roller Length, L3 |
1 m |
Roller Angle, Theta 1 |
30 deg |
Roller Angle, Theta 2 |
90 deg |
Contact Stiffness |
5000 kN/m |
Axial Rotation |
0 deg |
A Stinger component named ‘Stinger’ is created to model the S-Lay stinger. Explicitly Defined is selected as the stinger definition option. The Support Locations of the stinger are listed in table below.
Table: Support Locations on ‘Stinger’
Support Name |
X Coordinate (m) |
Y Coordinate (m) |
V-Rollerbox |
4.8 |
-6 |
V-Rollerbox |
4.8 |
-18 |
V-Rollerbox |
4.8 |
-30 |
V-Rollerbox |
4.8 |
-42 |
V-Rollerbox |
4.8 |
-54 |
V-Rollerbox |
4.8 |
-66 |
V-Rollerbox |
4.8 |
-78 |
V-Rollerbox |
4.8 |
-90 |
V-Rollerbox |
4.8 |
-102 |
V-Rollerbox |
4.8 |
-115 |
V-Rollerbox |
4.8 |
-130 |
V-Rollerbox |
4.8 |
-150 |
V-Rollerbox |
4.8 |
-175 |
V-Rollerbox |
4.8 |
-203 |
V-Rollerbox |
4.8 |
-233 |
A Vessel component named ‘Lay Vessel’ is created in the Vessel folder. This component is used to model the lay vessel. The Standard Vessel Profile option is selected from the Profile Options drop-down list. The overall dimensions of the vessel are listed in the table below.
Table: Properties of ‘Lay Vessel’
Property |
Value |
Length |
220 m |
Depth of Keel below Origin |
15 m |
Horizontal Offset from Origin |
110 m |
Create Solid Profile |
No |
The Vessel Reference Point is also defined on the Vessel component, the properties of which are listed in the table below.
Table: ‘Lay Vessel’ Reference Point
Property |
Value |
X Coordinate |
0 m |
Y Coordinate |
125 m |
Z Coordinate |
0 m |
The Stinger Location and Support Locations are also defined in the Vessel component, the properties of which are listed in the two tables below respectively.
Table: ‘Stinger’ Location
Property |
Value |
X Coordinate |
0 m |
Y Coordinate |
0 m |
Z Coordinate |
0 m |
Stinger Angle |
0 degrees |
Table: Support Locations on ‘Lay Vessel’
Support Name |
X Coordinate (m) |
Y Coordinate (m) |
Z Coordinate (m) |
Zero Gap Guide |
4.8472 |
128 |
0 |
V-Rollerbox |
4.8 |
115.8 |
0 |
V-Rollerbox |
4.8 |
103.2 |
0 |
V-Rollerbox |
4.8 |
91.4 |
0 |
V-Rollerbox |
4.8 |
79.2 |
0 |
V-Rollerbox |
4.8 |
67 |
0 |
V-Rollerbox |
4.8 |
54.8 |
0 |
V-Rollerbox |
4.8 |
42.6 |
0 |
V-Rollerbox |
4.8 |
30.4 |
0 |
V-Rollerbox |
4.8 |
18.2 |
0 |
V-Rollerbox |
4.8 |
6 |
0 |
Radii of Curvature are specified on the Vessel component. This involves specifying two Y-coordinates for tangent points and their corresponding radii of curvature, as listed in the table below, which the ‘Lay Vessel’ and ‘Stinger’ supports are aligned upon. Specifying radii of curvature should ideally be carried out over a number of design iteration steps in order to achieve the optimum configuration (see Example 15 – Shallow Water Rigid S-Lay for an example of this design process).
Table: Radii of Curvature on ‘Lay Vessel’
Radius of Curvature (m) |
Y Coordinate (m) |
Analysis Optimisation |
250 |
36 |
No |
100 |
-16 |
No |
The Vessel Offset component is used to specify the static offset that is to be applied to a vessel in an analysis. This example contains two Vessel Offset components, named ‘50m Offset’ and ‘100m Offset’ respectively. ‘50m Offset’ defines a surge offset of 50 m while ‘100m Offset’ defines a surge offset of 100 m.
A single Seabed component is created in the Model folder and is named ‘Rigid Seabed’. The default properties of a rigid seabed, with a zero coefficient of friction in the longitudinal and transverse directions and a slope of zero degrees, are left unchanged.