Components

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Components

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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 10

Project Sidebar for Example 10

 

Project Component

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 10 – Articulated S-Lay

Job Number

1-2-3-342

Engineer(s)

Wood Group

Location

Galway

In the case of this example, the default project-specific settings are used (e.g. metric unit system, default mesh settings etc.).

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Material Component

The Material component is used to define the physical properties associated with a particular material. This example contains one Material component, which defines the nonlinear material properties for X65 steel, as listed in the table below. The Material component is created in the Material folder and is 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

7850.0 kg/m3

Yield Strength

450 MPa

Allowable Stress

100 %

Allowable Strain

0.25 %

Expected Tension

0 kN

Nonlinear Axial Stiffness

No

Use Criteria Tension

Yes

 

Stress-Strain Curve for ‘X65 Steel’

Stress-Strain Curve for ‘X65 Steel’

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Pipe Section Component

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 ‘16’’ 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 ‘16’’ Pipe

Property

Value

Outer Diameter

406.4 mm

Thickness

20 mm

Normal Drag

1

Normal Inertia

2

 

Line Component

The Line component is created in the Line folder and is named ‘Pipeline’. This Line component contains 400 m of the Pipe Section component ‘16’’ Pipe(1)’.

 

Support Components

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 4 m. The properties of the ‘V-Rollerbox’ component are listed in the table below.

Table: Properties of ‘V-Rollerbox’

Property

Value

Support Length

1 m

Roller Length, L1

0 m

Roller Length, L2

1 m

Roller Length, L3

1 m

Roller Angle, Theta 1

30 deg

Roller Angle, Theta 2

90 deg

Contact Stiffness

5000 kN/m

 

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Tensioner Component

A single Tensioner component is created in the Stinger folder and is named ‘Tensioner’. The Type is specified as Linear, while the Coefficient Type is specified as Active with default Damper properties. ‘Zero-Gap Guide’ is used as the Tensioner Support.

 

Stinger Section Components

The Stinger Section component is used to model individual sections of a stinger. This example contains two stinger sections, stored in the Stinger folder, namely, ‘Upper Section’ and ‘Lower Section’. The same properties are assigned to each section, as shown in the first table below. The support locations for the both sections are also provided in the second table below.

Table: Properties for Stinger Sections

Property

Value

Section Type

Flexible

Length

36 m

Bending Stiffness

1.0E+7 kN.m²

Axial Stiffness

1.0E+9 kN

Torsional Stiffness

1.0E+10 kN.m²/rad

Weight in Air

10 kN

Buoyancy

75 kN

Drag Diameter

1 m

Normal Drag

1

Normal Inertia

2

Table: Support Locations for ‘Upper Section’ and ‘Lower Section’

Support Name

Distance (m)

V-Rollerbox

6

V-Rollerbox

18

V-Rollerbox

30

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Flex Joint Component

Flex Joint components are typically used to specify the properties of flexible or articulated joints between connecting pipe/stinger sections. In the case of this example a flex joint, named ‘Hinge’, is used to connect the various stinger sections together as well as to attach the entire stinger to the vessel. The table below provides a summary of the properties for this flex joint.

Table: Properties for ‘Hinge’

Property

Value

Type

Non-Linear

Curve

Automatic

Length

0.1 m

Weight in Air

1 kN

Weight in Water

0.5 kN

Positive Free Rotation Angle

14°

Negative Free Rotation Angle

14°

 

 

Stinger Component

A Stinger component is used to model the articulated stinger, named ‘Articulated Stinger’ in this example. Articulated S-Lay is selected as the stinger definition option. In the Buoyancy dialog, the Optimise Buoyancy option is set to ‘Yes’. The Stinger Sections for the stinger are given in the table below.

Table: Stinger Sections for ‘Articulated Stinger’

Stinger Section Name

Orientation Type

Section Orientation (°)

Flex Joint

Upper Section

Absolute

14

Hinge

Lower Section

Incremental

14

Hinge

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Vessel Component

A Vessel component named ‘Lay Vessel’ is created in the Vessel folder. This component models 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

0 m

Create Solid Profile

No

The Stinger Location and Support Locations are also defined on the Vessel component, the properties of which are given in the tables below respectively.

Table: ‘Articulated Stinger’ Location

Property

Value

X Coordinate

2.8 m

Y Coordinate

-88.1 m

Z Coordinate

0 m

Stinger Angle

180°

Table: Support Locations on ‘Lay Vessel’

Support Name

X Coordinate (m)

Y Coordinate (m)

Z Coordinate (m)

Angle (°)

Tensioner

4.8314

-7.8

0

-

V-Rollerbox

4.8

-20

0

-

V-Rollerbox

4.8

-32.2

0

-

V-Rollerbox

4.8

-44.4

0

-

V-Rollerbox

4.8

-56.6

0

-

V-Rollerbox

4.8

-68.8

0

-

V-Rollerbox

4.8

-81

0

-

Radii of Curvature for the supports along the vessel and stinger are to be user-defined also. See the table below for the properties defined in the Radii of Curvature dialog.

Table: Radii of Curvature Properties

Radius of Curvature (m)

Y Coordinate (m)

Analysis Optimisation

200

-64.1

No

150

-88.1

No

 

To complete the definition of the Vessel component, the Vessel Motion component ‘Lay Vessel RAOs’ is associated with the vessel by selecting it from the Vessel Motions drop-down list.

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Vessel Motion Component

The Vessel Motion component is used to specify the dynamic motions of a vessel, including first order (RAO) motions and second order (drift) motions. In the case of this example a Vessel Motion component, named ‘Lay Vessel RAOs’ is created in the Vessel folder. The vessel motion option RAO + Drift is selected from the Motion Type drop-down list. The RAO file included in the example directory, ‘Lay Vessel.rao’, is loaded into the component through the RAO File dialog. These RAOs are supplied in the MCS Kenny format, so the remaining options are left unchanged.

To view the RAO data, a PipeLay RAO Report can be generated by selecting Yes on the Plot RAOs drop-down list. This RAO Report contains graphs of the RAO and phase angles for each of the translational and rotational DOFs for the vessel. The Heave RAO plot is included in the figure below as an example.

Heave RAOs for Lay Vessel

Heave RAOs for Lay Vessel

 

Seabed Component

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.

 

Wave Component

A single Wave components is added to the Load folder, named ‘Regular Wave’. This Wave component is used to model the regular wave included in this example. The Regular option is selected from the Type drop-down list and the properties given in the table below.

Table: Properties of ‘Regular Wave’

Property

Value

Amplitude

1.5 m

Period

10 s

Direction

180.0°

Phase

0.0°

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