Results Tab - Stage Results
You can access results from any analysis stage via Open Results Directory, but it is more straightforward to use the options in the lower sub-section of Analysis Results. Here you select the stage you are interested in from the Stage drop-down list and then click on one of the buttons below the drop-down list to open the various results files. The content of these files is now briefly summarised.
When you click on Open Animation, the Dynamic Display module is launched and the animation file (analysis.pdp) generated by PipeLay for your analysis stage is loaded. The Dynamic Display module provides a sophisticated facility for viewing animations of your analysis results.
The tabular output file (analysis.tab and analysis.csv) contains a summary of the main analysis results. The top section of the file contains general information on the PipeLay project (this is the information specified on the Project component) as well as more specific information on the analysis itself (not in analysis.csv for simplicity).
In the case of static analyses, the next section of the file is the Static Solution Summary section. The first part gives a summary of the fundamental model inputs (e.g. pipeline geometric and structural properties) and some standard computational outputs (e.g. pipe tension, touchdown, projected span length etc.). This section is included mainly for input data verification purposes (not in analysis.csv for simplicity). Also provided is a summary of output parameters at critical locations in the model – at the touchdown point, at each support location and at the location of maximum bending in the sagbend region.
Further tables present detailed results for every node in the model. This allows an in-depth analysis of displacements, stresses/strains, support reactions and separations, tensions and bending moments for the whole model. In the case of static analyses, the results presented are a snapshot of values at the end the static analysis. In the case of dynamic analyses, extreme values and ranges are computed over time and presented in tabular format.
The analysis.tab file (plain text tabular output) can be opened using the Open Tabular Data button while the analysis.csv file (comma separated values tabular output) can be opened using the Open Tabular CSV button (opens in Windows™ Excel if available). The tabular output can be selectively enabled or disabled by using the control on the Installation Stages Tab
PipeLay generates individual plot files for every graph presented in the analysis report file. Plots are generated by default if the Automated Postprocessing is enabled for this stage on the Installation Stages Tab. Additional plots are generated if a Custom Postprocessing component is referenced for this stage on the Installation Stages Tab. The Open Plot Files button allows direct access to the files via the PipeLay Plotting module. This allows you greater flexibility in the presentation of results. For example, the Plotting module allows you to zoom in on a particular area of interest, and also to superpose plots to facilitate comparison of results.
The analysis report file (analysis.prp) contains a summary of the user inputs and also contains all the results generated by the automatic postprocessing and any custom postprocessing that may have been specified for the analysis. The report file is in rich-text format and contains embedded tables and graphs. Except for the plots, the content is similar to the tabular output file, although more succinct. Note that the plots are produced in ‘report-ready’ format – you can simply copy and paste the graphs from the analysis report file into other documents.
Each run of the PipeLay analysis engine generates a detailed output file, analysis.out, which can be examined after the run has ended. This is again a plain text file. It contains a substantial amount of information, including full details of the finite element discretisation, model properties tabulated on an element-by-element basis, a summary of the environment and loading to which the pipeline is subjected, and details of the results of the analysis. While it is comprehensive, it is meaningful only in the context of an understanding of the PipeLay finite element model, and so this is a file you will reference only infrequently.
If you invoke Plot RAOs on the Vessel Motion component, an RAO report file (analysis.rrp) is generated during each dynamic installation stage and is available for inspection by clicking on Open RAO Report. General project information is given at the top of the file. This is followed by graphs of the RAOs and phases for the translational and rotational degrees of freedom for the vessel. A group of graphs is generated for each heading specified in the RAO file.
When you run an analysis, PipeLay performs some preprocessing of the information called the cable pre-static step, unless you opted to bypass this step in the Properties tab of the Analysis component. During the cable pre-static step, PipeLay analyses the initial tension in the cables, the position of cable nodes and so on. At this end of this step, PipeLay outputs the results of the step to a cable solution file called analysis_cpss.pdp. The View Cable Solution button allows you to open this file using the Dynamic Display module.
If you have defined your pipe profile via the Radii of Curvature dialog on the Vessel component and set the any Analysis Optimisation entry to Yes then a Support Elevation Optimisation step will have been run. After this optimisation process has run, a csv file containing a summary of the support adjustments is produced. The View Support Data button allows you to open this file using Microsoft Excel.
If you invoke Generate Vessel Time History, PipeLay generates motion time histories for the nominated vessel for all 6 vessel degrees of freedom. These are available in plot format for inspection via Open Plot Files in the Vessel Motion Timetrace History section of the Results tab. These are standard PipeLay plots displayed via the Plotting module, so no further discussion is required here.
The time histories above are also output to a single text file that can then be used as input to a Vessel Motion component, which uses Timetrace as the Motion Type. This text file is located in the results directory, under the ‘Vessel Motion’ sub-directory, and is named analysis.ttr.