The Analysis component is used to specify the various inputs for a PipeLay analysis. The Analysis component allows you to gather together a set of components of various types, such as pipelines, vessels, waves and so on, from all of those defined in a project file, and to perform various types of analyses using these components. In this example, the Analysis component is named ‘Articulated S-Lay Analysis’. The following sections provide a description of the various inputs for the analysis.
The Properties tab allows you to specify the options that are to be applied to all analysis stages of a particular model. In this example the Model is selected as ‘Model’ and the Contact Modelling option is defined as Simple. The Swivel option is selected as ‘About Horizontal Axis’. The Tolerance dialog in the Dynamic section has the properties listed in the table below.
Table: Dynamic Tolerance Properties
Property |
Value |
Tolerance Measure |
0.001 |
Maximum Number of Iterations |
1000 |
Small Torque Value |
1 x 106 Nm |
The Installation Stages tab is where you define the various stages in your analysis. In this example there are two stages. The first stage corresponds to an initial static analysis while the second one corresponds to a dynamic analysis, which restarts from the initial static analysis. A regular wave is applied in the dynamic stage. The table below shows the time variables used in the dynamic stage.
Table: Time Variables for Dynamic Analysis
Property |
Value |
Time Step Type |
Fixed |
Start Time |
0 s |
End Time |
50 s |
Time Step |
0.05 s |
Ramp Type |
Nonlinear |
Ramp Time |
20 s |
On the Criteria tab, you can specify installation criteria for each installation stage that is created in the Installation Stages tab. In this example, criteria are only applied to the initial static stage as the other stages restart from this stage. The table below provides details of the specified criteria.
Table: Criteria Properties for Static Stage
Property |
Value |
Criteria |
Tension |
Type |
Tensioner |
Minimum Value |
218 kN |
Maximum Value |
219 kN |
Iterate On - Type |
Seabed Connection Point |
Iterate On - Name |
Seabed Connection |
Iterate On - Vector |
Global Y |
Tolerance – Max Iterations |
1000 |
Tolerance – Min Adjustment |
0.01 m |
Tolerance – Max Adjustment |
50 m |
Multi-Pass |
Yes |
You can use the Summary Postprocessing tab to request output from various parameters at crucial locations throughout the installation process. In this example, a number of parameters are selected for summary postprocessing, as detailed in the table below.
Table: Summary Postprocessing
Type |
Component |
Parameter |
Criteria |
Tensioner |
Tension |
Criteria |
Pipeline(1)_16’’ Pipe(1) |
Bending Strain |
You are now ready to run the analysis. While the analysis is running, you can observe the analysis progress and check for warnings or errors on the Progress tab.