tutorial dnv os f101 2012

AutoPIPE 9.6 i

Tutorial-DNV-OS-F101-2012.docx Rev 3

AUTOPIPE© DNV OS F101 (2012) CODE COMPLIANCE

CALCULATIONS IN AUTOPIPE

Rev. No. Date Prepared by Description 0 08/07/2013 Bilal Shah Initial structure for review / completion 1 8/12/2013 Josh Taylor Updated images and procedure 2 8/19/2013 Josh Taylor 3 9/5/2013 Josh Taylor Updated section 14 4

AutoPIPE 9.6 ii


TABLE OF CONTENTS

1 Introduction ......................................................................................................................................................... 1

2 Model Overview ................................................................................................................................................... 1

3 Workflow - DNV-OS-F101 Code Compliance .......................................................................................................... 2

4 Review the General Model Options dialog ............................................................................................................ 4

5 Review Pipe Properties ......................................................................................................................................... 5

6 Review Pressure & Temperature Properties .......................................................................................................... 7

7 Review Soil Properties for the Buried Pipe Portion at Sea Bed ............................................................................... 7

8 Define/Review Static Earthquake Load Cases ........................................................................................................ 9

9 Define Wind Load Case ......................................................................................................................................... 9

10 Define Wave Load Cases ..................................................................................................................................... 10

11 Set Up the Buoyancy Dialog ................................................................................................................................ 11

12 Defining Interference Loads ................................................................................................................................ 11

13 Define Accidental Load ....................................................................................................................................... 11

14 Update Pressure Values For Operating Pressure P1 ............................................................................................. 12

15 Define/Review Static Analysis Set ....................................................................................................................... 14

16 Setting Up DNV 2012 Result Options Dialog ........................................................................................................ 16

17 Setting Model Result Options ............................................................................................................................. 18

18 Creating a Legacy DNV 1981 Combination ........................................................................................................... 18

19 Creating More Load Controlled Combinations ..................................................................................................... 19

20 Generate Output Report ..................................................................................................................................... 21

21 View Code Stress Color Plots ............................................................................................................................... 23

22 View Code Stress on the Result Grid ................................................................................................................... 24

23 Additional Notes ................................................................................................................................................. 24

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1 INTRODUCTION

The August 2012 revision of DNV offshore standard, DNV-OS-F101, Submarine Pipeline Systems is supported by AutoPIPE version 9.6. This document provides a quick walk through for entering input data, analyzing and generating code compliance reports for a model with piping code selected as DNV Offshore 2012.

The menu options and dialog controls in this tutorial are displayed in Green Italic.

Additional notes and tips are displayed in Blue Italics.

2 MODEL OVERVIEW

The initial model geometry for this tutorial "DNV-OS-F101-INITIALMODEL.DAT" has been provided with this tutorial. The model contains a pipeline with two vertical legs and a buried horizontal pipe representing pipeline resting on sea bed. Most of the input data for the model has been provided in the initial model. Following is an overview of the final model:

Material Properties

Pipe Material: CMN-415 (for Pipe ID B and C), CMN-450 (for Pipe ID A)

Composition: CS (Carbon Standard)

Pipe Identifiers with Diameter, thickness, corrosion and fabrication thickness data

Load Cases

Operating Pressure and Temperature data for 3 ‘T’ cases

Earthquake loading cases: E1 and E2

Wind loading cases: W1 and W2

Wave loading cases: Wave1, Wave2 and Wave 3 (One case for accidental)

User loads: U1 and U2 (Interference loads, may be from trawling)

Soil Properties: SND11A

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3 WORKFLOW - DNV-OS-F101 CODE COMPLIANCE

Review the General Model Options properties

Define Model Geometry and restraints / supports

Set up the pressure and temperature values in the model

Assign soil properties to the buried portion of the model. This includes assigning soil stiffness values, soil overburden stresses and seismic wave data associated with the soil. Refer to “Tutorial - Soil Overburden and Seismic Wave Propagation in AutoPIPE v9_5.pdf” for further details

Model Setup

Defining Model Geom

etry Defining Pressure &

Temperature

Define soil properties for buried piping

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Define loads on the model like Functional, Environmental, Interference and Accidental loads. Adjust Buoyancy properties for the model

Modify the analysis set, select applicable load cases, enable gaps/friction if non-linear soil analysis is required.

Set the required Model Result Options and DNV 2012 Result options including design factors and load combinations.

Finally review the code compliance output report, generate color plots for code stresses and review the results in the output grids

Define loads M

odel analysis Post processing

Review results

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4 REVIEW THE GENERAL MODEL OPTIONS DIALOG

Open the initial model, DNV-OS-F101-INITIALMODEL, and take note of the Piping Code, Edition, default unit system, material library.

AutoPIPE has a material library specific to DNV 2012, named DNVM2012. The DNVM2012 library is the default selection for DNV 2012 and contains three materials: C-MN, DUPLEX Stainless Steel and Martensitic Stainless Steel. These materials can be reviewed through Tools/Library…

Field Selection for Walkthru Comments

Piping Code DNV Offshore DNV Offshore now includes two year types: 1981 and the new 2012

Edition 2012 Analyzing the DNV 2012 code standard will be the main topic of this tutorial

Unit file name - Input / Output

SI / SI The DNV foundation in Norway uses the International System of Units as the default

Number of thermal/pressure cases

3 Enter the number of thermal/pressure cases required. Additional thermal cases should be defined if seismic wave propagation effects are to be considered.

Ambient temperature 20°C This is the ambient temperature defined for the model.

The cold Young’s modulus and cold allowable will be fetched from the library at this temperature.

Libraries - Component AUTOPIPE This is the default component library for DNV 2012 code.

Libraries - Material DNVM2012 This is the default library for DNV Offshore 2012, created specifically for this code.

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Press OK on the General Model Options dialog.

5 REVIEW PIPE PROPERTIES

Open the Pipe Properties dialog next. For the selected model, review the pipe properties for Pipe ID A, B and C. While doing so, take note on how the fabrication thickness is calculated. Also note the Fabrication Factor, Ovality, Minimum Yield and Minimum Tensile. Fabrication Factor and Ovality fields are for DNV 2012 only.

For Pipe ID A, update the pipe material from CMn-415 to CMn-450 and note the effect on the other fields in the dialog.

You would need to define the properties for the metallic piping on the dialog:

Enter the following on the Pipe Properties dialog for PipeID A:

Field PipeID A PipeID B and C Nominal Diameter 200 mm 200 mm Schedule STD STD Corrosion Allow 0.975 mm 0.975 mm Specific gravity for contents 1.00 1.00 Pipe Material CMN-450 CMN-415 Rest of the fields Default

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Press OK on the Pipe Properties dialog.

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6 REVIEW PRESSURE & TEMPERATURE PROPERTIES

Open up the Pressure & Temperature dialog / Grid. Note the new fu and fy de-rating fields for DNV 2012, where the values come from and how user may be able to define his own de-rating values by updating the Material Library.

Press OK to close the dialog.

7 REVIEW SOIL PROPERTIES FOR THE BURIED PIPE PORTION AT SEA BED

Open the Soil Properties dialog for the only Soil Identifier in the model, SND11A.

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Click on the Enter Soil Properties button to Invoke Edit Soil Properties dialog. Select the Soil Type as Medium Sand. Click the Generate button to generate the Soil Stiffness Properties:

Press OK to close the Edit Soil Properties dialog. Press OK to close the Soil Properties dialog.

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8 DEFINE/REVIEW STATIC EARTHQUAKE LOAD CASES

Open the Static Earthquake dialog. Review the static seismic load cases defined in the model.

Press OK to close this dialog.

9 DEFINE WIND LOAD CASE

Open the Wind dialog. Define two wind load cases in the model. Set both of these wind cases, W1 and W2, to the ASCE-7-98 wind specification type. Set focus to the W1 row and press the Modify button; take note of the default values and press OK to close the dialog. Set W2 to the Global +Y wind direction. Press OK to close the Wind dialog.

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10 DEFINE WAVE LOAD CASES

Open the Wave Load dialog and navigate to the wave data name WAVE2. Note the values used and update the Load case to W2.

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Press OK to close the Wave Load dialog.

11 SET UP THE BUOYANCY DIALOG

Open the Buoyancy dialog.

When the dialog appears as above, press OK to close the dialog.

12 DEFINING INTERFERENCE LOADS

Note a 30mm Imposed Support Displacement on the A00 Anchor, which is the U1 case in the model. This will be used as an interference load for the analysis.

13 DEFINE ACCIDENTAL LOAD

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Open the Wave dialog again. Create a new wave data name, Wave3. Set this to a Load case of U2. This will be an extreme wave case for the model, to be used in the Accidental Load section of the DNV analysis. Fill in the fields as shown below.

Press OK to close the Wave Load dialog.

14 UPDATE PRESSURE VALUES FOR OPERATING PRESSURE P1

Update pressure case P1 using the Local Incidental Pressure Calculation tool in the General tab of the DNV 2012 Result Options dialog. The local incidental pressure calculation group on the General tab of DNV 2012 Result Options dialog is used to update the pressure values at each point in the model for the selected pressure case based on the reference elevation, reference pressure at the reference elevation, and the specific gravity of internal fluid.

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Note that the pressure values at each point in AutoPIPE for the pressure load cases are considered as local incidental pressure and are used as such in the calculations. Press Update to update the P1 pressure case. If the change was successful, a notification dialog will display. Press OK to close the note and again on the dialog. We will return to this dialog in a later section to cover the other tabs.

Pressure Before Local Incidental Pressure Calculation Pressure After Local Incidental Pressure Calculation

0.000 psi 0.6991 psi

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15 DEFINE/REVIEW STATIC ANALYSIS SET

Open the Analysis Sets dialog and open Analysis Set No. 1.

Press OK on the Nonlinear Analysis dialog when it looks like the image above.

Press OK on the Analysis Sets dialog and press Yes on the Confirm dialog to run the analysis on the model.

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Finally press OK on the Analyze All dialog to run the analysis.

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16 SETTING UP DNV 2012 RESULT OPTIONS DIALOG

Open the new DNV 2012 Result Options dialog and navigate to the Code Category Options tab.. Note the following on Use Nom. Thickness checkbox:

When the Use Nom. Thickness check box is checked, AutoPIPE will use nominal thickness for in stress calculations for that category. When unchecked, AutoPIPE will use the characteristic wall thickness values as suggested by DNV-OS-F101 table 5-6 (refer to the DNV reference section in the online help for this table). The default state of the checkbox is unchecked for all categories.

Go through the design factor tab and where the values are used in calculations.

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Then go to the code combinations tab. Select the Category Components for the ULS and ALS categories as shown below. The accidental category will use U2, which is the extreme wave load created earlier. Let the ALS Interference category use U1 case.

On the General tab, review the online help for the Apply ASD check to Bends only and the top two fields and where to change these.

Note: If None is selected for any of the cases, no load for that section will be applied to the appropriate combination.

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17 SETTING MODEL RESULT OPTIONS

Open the Result Model Options dialog. Note that most of these options affect Legacy AutoPIPE DNV Offshore 1981 results and do not affect the new DNV 2012 results. The highlighted fields below affect DNV 2012.

Note: The active options above that are not highlighted can be edited by the user, but will not affect the output results of the model.

18 CREATING A LEGACY DNV 1981 COMBINATION

AutoPIPE does not create default legacy code combinations for categories like expansion / occasional loads by default. However, the categories are available and user can create combinations for these categories. The results for these categories would be same as were reported for DNV 1981, except for Hoop stress category, which is updated according to DNV 2012.

To create a legacy code combination, open the Load Combination dialog and navigate to the Code Comb. tab. Press the New button to open the User Code Combinations dialog. Fill out the dialog as shown below to create an Ambient to T3 code combination.

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Press OK to close this dialog and introduce a new user-defined code combination.

19 CREATING MORE LOAD CONTROLLED COMBINATIONS

Load controlled categories are defined based on the default combinations generated by AutoPIPE. The default combinations are generated using the factors and components defined under Code Combinations tab of DNV 2012 dialog.

Duplicate the Buck. Comb. Category combination GRTP1W1U1_U{1}, by highlighting the row and pressing the Duplicate Selection button. Update the duplicate combination created by changing some of the factors and component load cases for that combination. Rename the combination with a more meaningful name, “10-year wave”.

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Press the OK button to close the User Code Combinations dialog, and then OK again to close the Code Combinations dialog.

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20 GENERATE OUTPUT REPORT

Finally, you can generate an output report through the Batch Report dialog. Select Code Compliance, Model Listing, Result Summary and Analysis Summary check boxes.

The output report will display the selected sections. A couple points from the model are shown below as code compliance output.

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Also perform the comparison of user updated model with the model the updated model which is created after running this tutorial for him to compare results.

Compare the existing output report (DNV-OS-F101-FINALMODEL.OUT) with the recently created output file (DNV-OS_F101_INITIALMODEL.OUT). Note that the output values, if done correctly, should be the same.

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21 VIEW CODE STRESS COLOR PLOTS

Open the Code Stresses result dialog. Accept the defaults by pressing OK. Note the highest stress in the model, located on point A40 +.

Moreover, you can also see all the code stresses at selected point by going through the Stresses dialog:

Press the Escape key to close down the color plot view.

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22 VIEW CODE STRESS ON THE RESULT GRID

You can view all the stresses at a point using the result grid. Invoke the Result Review dialog by invoking Result > Grids. The graphics and the grip work synchronously as a point selected in the grid is automatically focused on the GUI and vice versa.

Close the Result Review after reviewing the results dialog.

Note: AutoPIPE provides the functionality of exporting the result grid or the model input grid to the user. Use the options under File > Export to export your data to different formats.

23 ADDITIONAL NOTES

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