FlawPro usermanual03_09

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FlawPRO Version 3:

USER MANUALFLAWPROTMVersion 3: FATIGUE LIFE ASSESSMENT

OF WELDED PIPES WITH AND WITHOUTREELING ON-SHORE

A program for determining the effects of reeling andconventional installation on the service lifetimes of

reeled pipes containing weld flaws.

Prepared by :

Dr. G. Graham ChellSouthwest Research Institute

San Antonio, Texas, U.S.A.

In col laborat ion wi th:

INTERPROBoerne, Texas

March 2009


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Copyright 2009

Southwest Research Institute(SwRI)

All Rights Reserved

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Acknowledgments

The full-scale validation of FlawPROTM, as well as certain software enhancements, were performed under a Joint IndustryProgram (JIP) entitled "Validation of a Methodology for Assessing Defect Tolerance of Welded Reeled Risers", which wasconducted by SwRI for the offshore industry. SwRI is pleased to acknowledge the advice, encouragement, and financialsupport received from the following JIP member companies: ChevronTexaco, ExxonMobil, Shell, Technip, Tenaris, andTotal. Special acknowledgements are also due to Paulo Gioielli and Jaime Buitrago of ExxonMobil who championed theJIP formation, as well as to Frans Kopp of Shell who had the vision to initially support the development of FlawPRO. Theclad pipe version of FlawPRO was developed with support from Shell.


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Table of Contents

Acknowledgments .......................................................................................................................................................................iiGETTING STARTED WITH FlawPRO .........................................................................................................................................1

Overview of FlawPRO................................................................................................................................................................1Computer and Hardware Requirements....................................................................................................................................1Installing and Un-installing ......................................................................................................................................................... 1

Installation...............................................................................................................................................................................1Uninstalling FlawPRO ............................................................................................................................................................ 1

Registering Your Copy of FlawPRO ..........................................................................................................................................2Setting Units in FlawPRO .......................................................................................................................................................... 4Change Request and Error Report Form ..................................................................................................................................4Nomenclature ............................................................................................................................................................................. 5View Menu: Viewing FlawPRO Input Screens .......................................................................................................................... 5Help Menu: Using FlawPRO's On-line Help.............................................................................................................................. 5

ANALYSIS FILE OPERATIONS................................................................................................................................................... 6Creating A New Analysis File .................................................................................................................................................... 6Opening An Existing Analysis File ............................................................................................................................................. 6Saving Or Copying An Analysis File.......................................................................................................................................... 6

GRID AND PLOT PROCEDURES................................................................................................................................................ 7Deleting A Row From The Grid.................................................................................................................................................. 7Adding Row To Grid................................................................................................................................................................... 7Deleting All Rows From The Grid .............................................................................................................................................. 7Importing Data From A File........................................................................................................................................................ 7Exporting Grid Data To A File....................................................................................................................................................8Export Plot .................................................................................................................................................................................. 8Print Plot ..................................................................................................................................................................................... 8

ENGINEERING CAPABILITIES AND LIMITATIONS ................................................................................................................. 9ANALYSIS OPTIONS SCREEN ................................................................................................................................................. 11VARIABLES SCREEN ................................................................................................................................................................ 12

Setting Up Sensitivity Analysis Variables................................................................................................................................ 12Establishing the Range of Primary Independent Variables (PIV)........................................................................................... 13Defining Discrete Values for Secondary Independent Variables (SIV) .................................................................................. 14

GEOMETRY SCREEN (Unclad Pipe)........................................................................................................................................ 15Defining Pipe and Crack Geometry (Unclad Pipe).................................................................................................................. 15Defining Initial Crack Size Distribution (Unclad Pipe) ............................................................................................................. 16Exporting Initial Crack Size Distributions (Unclad Pipe) ......................................................................................................... 17Plotting Initial Crack Height Versus Length Distributions (Unclad Pipe)................................................................................ 18

GEOMETRY SCREEN (Clad Pipe) ............................................................................................................................................ 19Defining Pipe and Crack Geometry (Clad Pipe) ......................................................................................................................... 19Defining Initial Crack Size Distribution (Clad Pipe)..................................................................................................................... 20Exporting Initial Crack Size Distributions (Clad Pipe)................................................................................................................. 21Plotting Initial Crack Height Versus Length Distributions (Clad Pipe)........................................................................................ 22MATERIALS SCREEN................................................................................................................................................................ 24

Material Properties ................................................................................................................................................................... 24Reeling and Installation (Ferritic Material)............................................................................................................................... 24

Specifying Pipe Material Behavior for Reeling and Installation Fatigue (Ferritic Material)................................................ 24Defining Pipe Weld Strength and Fracture Properties for Installation and Reeling Fatigue (Ferritic Material)................. 25Plotting The JR Curve (Ferritic Material) ............................................................................................................................. 26Defining and Plotting The True Stress-Strain Relationship for Reeling and Installation (Ferritic Material) ...................... 27Defining Reeling Fatigue: Paris Equation Constants (Ferritic Material) ............................................................................. 28Plotting Reeling Fatigue Paris Equations (Ferritic Material) ............................................................................................... 30Defining Installation Fatigue: Paris Equation Constants (Ferritic Material)........................................................................ 30Plotting Installation Fatigue Paris Equations (Ferritic Material).......................................................................................... 32

Reeling and Installation (Clad Material) ..................................................................................................................................33Specifying Pipe Material Behavior for Reeling and Installation (Clad Material)................................................................. 33Defining Clad Strength and Fracture Properties for Installation Fatigue (Clad Material)................................................... 35


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Plotting The JR Curve (Clad Material)................................................................................................................................. 36Defining and Plotting The True Stress-Strain Relationship for Reeling and Installation (Clad Material) .......................... 37Defining Reeling Fatigue: Paris Equation Constants (Clad Material)................................................................................. 39Plotting Reeling Fatigue Paris Equations (Clad Material) ................................................................................................... 40Defining Installation Fatigue: Paris Equation Constants (Clad Material)............................................................................ 41Plotting Installation Fatigue Paris Equations (Clad Material).............................................................................................. 42

Service (Ferritic Material)......................................................................................................................................................... 43Specifying Pipe Material Behavior for Service Fatigue (Ferritic Material) .......................................................................... 43Defining Pipe Weld Strength and Fracture Properties for Service Fatigue (Ferritic Material) ........................................... 43Defining and Plotting The True Stress-Strain Relationship for Service (Ferritic Material)................................................. 44Defining Service Fatigue: Paris Equation Constants (Ferritic Material) ............................................................................. 45Plotting The Service Fatigue Paris Equations (Ferritic Material) ........................................................................................ 46

Service (Clad Material)............................................................................................................................................................. 48Specifying Pipe Material Behavior for Service Fatigue (Clad Material)..............................................................................48Defining Clad Strength and Fracture Properties for Service Fatigue (Clad Material)........................................................ 49Defining and Plotting The True Stress-Strain Relationship for Service (Clad Material) .................................................... 50Defining Service Fatigue: Paris Equation Constants (Clad Material)................................................................................. 51Plotting The Service Fatigue Paris Equations (Clad Material)............................................................................................ 52

LOADS SCREEN ........................................................................................................................................................................ 53Defining Pipe Loads ................................................................................................................................................................. 53Reeling and Installation............................................................................................................................................................ 53

Defining Reeling Loads ........................................................................................................................................................ 53Defining The Pipe Installation Fatigue Spectrum................................................................................................................ 54Scaling the Pipe Installation Spectrum ................................................................................................................................ 56Displaying The Scaled Installation Spectrum...................................................................................................................... 56Specifying the Worst Case Installation Stress..................................................................................................................... 57

Service...................................................................................................................................................................................... 58Defining The Pipe Service Fatigue Spectrum ..................................................................................................................... 58Scaling the Pipe Service Spectrum ..................................................................................................................................... 59Displaying The Scaled Service Spectrum ........................................................................................................................... 60Specifying the Number of Service Periods.......................................................................................................................... 61Specifying the Worst Case Service Stress.......................................................................................................................... 62

Weld Geometrical Discontinuities ............................................................................................................................................ 62Defining Normalized Membrane Stress Due to Weld Discontinuity ................................................................................... 63Defining Normalized Pipe Bend Stress Due to Weld Discontinuity .................................................................................... 64Defining Normalized Stress Due to Misalignment Discontinuity......................................................................................... 66Defining Weld Details for BS 7910 Stress Calculations...................................................................................................... 66

CALCULATION AND RESULTS SCREEN ............................................................................................................................... 68Analyzing and Generating Line Plots ...................................................................................................................................... 68Creating A Damage History ..................................................................................................................................................... 68Using The Error Messages Memo ........................................................................................................................................... 68Warnings and Errors ................................................................................................................................................................ 68Using The Calculation Parameters/Results Table .................................................................................................................. 75Creating and Using The Run Details Report ........................................................................................................................... 75

EXAMPLE DATA FILE................................................................................................................................................................ 76GLOSSARY ................................................................................................................................................................................. 77

Analysis Options....................................................................................................................................................................... 77Applied Axial Loads.................................................................................................................................................................. 77Brittle Failure ............................................................................................................................................................................ 78BS 7910.................................................................................................................................................................................... 78Clad Material ............................................................................................................................................................................ 79Clad Pipe .................................................................................................................................................................................. 79Crack Geometries .................................................................................................................................................................... 79Crack Tip Driving Forces ......................................................................................................................................................... 79Crack Transitioning .................................................................................................................................................................. 79Critical Crack Size.................................................................................................................................................................... 80Cycles Factor............................................................................................................................................................................ 80Cyclic Stress Range................................................................................................................................................................. 81Cyclic Threshold....................................................................................................................................................................... 81Damage Accumulation ............................................................................................................................................................. 81Default Values for Inputs.......................................................................................................................................................... 81Dependent Variables................................................................................................................................................................ 81DNV-RP-F108 .......................................................................................................................................................................... 81Ductile Failure........................................................................................................................................................................... 82End-of-Life Conditions.............................................................................................................................................................. 82Fatigue Crack Growth During Installation................................................................................................................................ 83


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Fatigue Crack Growth During Reeling..................................................................................................................................... 83Fatigue Crack Growth During Service..................................................................................................................................... 83Fatigue Crack Growth Library.................................................................................................................................................. 84Ferritic Material......................................................................................................................................................................... 87Final Crack Size ....................................................................................................................................................................... 87Flaw Offset ............................................................................................................................................................................... 87Geometrical Discontinuity ........................................................................................................................................................ 87Initial Crack Sizes..................................................................................................................................................................... 88J-integral Crack Tip Driving Force ........................................................................................................................................... 88JR-Curve................................................................................................................................................................................... 89Load Control ............................................................................................................................................................................. 90Load Step ................................................................................................................................................................................. 91Low Cycle Fatigue Crack Growth Due To Reeling ................................................................................................................. 91Maximum Allowable Initial Flaw Sizes (MAIFS)...................................................................................................................... 91Mean Stress Factor .................................................................................................................................................................. 91Membrane Stress ..................................................................................................................................................................... 91Misalignment ............................................................................................................................................................................ 92Misalignment Bend Stress Factor............................................................................................................................................ 92Misalignment Geometrical Discontinuity ................................................................................................................................. 92Net Section Yield Load............................................................................................................................................................. 93Normalized Stress Variation .................................................................................................................................................... 93Paris Equations for Installation Conditions.............................................................................................................................. 94Paris Equations for Service Conditions ................................................................................................................................... 95Paris Equations Adapted for Reeling Conditions.................................................................................................................... 95Pipe Bend Stress...................................................................................................................................................................... 96Plastic Strain............................................................................................................................................................................. 97Pre-Service Reels .................................................................................................................................................................... 97Pre-Straining............................................................................................................................................................................. 97Primary Independent Variables (PIV) ...................................................................................................................................... 97Ramberg-Osgood Equation ..................................................................................................................................................... 98Range Scale Factor ................................................................................................................................................................. 99Reeling...................................................................................................................................................................................... 99Reeling Life...............................................................................................................................................................................99Residual Stress Due to Reeling............................................................................................................................................... 99Residual Stress Due to Welding............................................................................................................................................ 100Runout .................................................................................................................................................................................... 100Saturation Tear Length .......................................................................................................................................................... 100Scaled Spectrum .................................................................................................................................................................... 100Scenario File...........................................................................................................................................................................100Secondary Independent Variables (SIV) ...............................................................................................................................100Service Life.............................................................................................................................................................................101Service Period ........................................................................................................................................................................ 101Strain Control..........................................................................................................................................................................102Stress Concentration Factor .................................................................................................................................................. 102Stress Intensity Factor ........................................................................................................................................................... 102Stress Ratio, R ....................................................................................................................................................................... 102Tearing Due to Reeling .......................................................................................................................................................... 102Tear-Fatigue Due to Reeling ................................................................................................................................................. 102Threshold................................................................................................................................................................................ 103Toughness..............................................................................................................................................................................103True Stress-True Strain..........................................................................................................................................................103Unit Sets ................................................................................................................................................................................. 103Weight Function ..................................................................................................................................................................... 104Weld Cap Width ..................................................................................................................................................................... 105Weld Geometrical Discontinuity............................................................................................................................................. 105Weld Root Width .................................................................................................................................................................... 105Weld Stress Concentration Factor (SCF)..............................................................................................................................106Yield Load...............................................................................................................................................................................106


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GETTING STARTED WITH FlawPRO

Overview of FlawPRO

FlawPRO will enable the practicing engineer to assess the effects of pre-service reeling, installation fatigue and servicefatigue on the lifetimes and flaw tolerances of welded pipes that may contain pre-existing flaws, such as crack-like defects,and are subjected to variable amplitude fatigue loading. The program is designed to facilitate sensitivity analyses in order toenable the effects of changes in input parameters on the lifetimes and flaw tolerances of reeled and installed pipes to bereadily determined. The results of calculations are displayed in chart and tabular form that can be easily exported and usedin engineering reports.FlawPRO Help Utility: 3/11/2009 6:47 PM

Version History

V3.50 March-2009: FlawPRO algorithms were extended to clad pipes. Clad pipe analysis features are available only toselected users.

V3.00.33 13-November-2007: FlawPRO was upgraded to operate under the Vista(r) operating system. There were nosignificant changes to its algorithms to make it compatible with the Microsoft Vista operating system.

V3.00.27 07-December-2006: This version incorporated new features, an extended help facility, and improved algorithms.

V2.00.04 9-April-2004: This was a major upgrade with new features and some reorganization of the graphical user interface

V1.01.02 21-August-2003: This version contained minor revisions to the original code and required users to register thecode.

V1.00.00 29-October-2002: This was the original issue of the code to users.

Computer and Hardware Requirements

In order to execute FlawPRO, personal computers must meet the following minimum hardware requirements:

Microsoft Windows XP or greater and Internet Explorer v5.5 Pentium 1GHz microprocessor unit or better A minimum of 256 megabytes of random access memory (RAM), although more RAM will improve performance A minimum of 64 megabytes of free disk space on the hard drive prior to installation

A color video display monitor with 800 x 600 resolution or better A mouse unit compatible with Microsoft Windows

Installing and Un-installing

Warning Note: If you are using previous versions of FlawPRO, you should first backup any analysis files (e.g. scenario ordata files such as *.flp files) that you wish to save and uninstall the old version of FlawPRO prior to installing the new

version of FlawPRO. If you fail to do this, it is possible that the new version of FlawPRO will overwrite some data or codefiles during the installation process, and such data will be permanently lost.

Installation

To install the software, insert the CD into the drive of the computer. Select Start, and then choose Run. Type x:FlawProSetup.exewhere x:is your CD drive. The automatic installation process will begin. Follow the instructions that

appear on the screen to complete the installation. The installation is complete when you reach a screen prompting you torestart your computer.

Uninstalling FlawPRO

To uninstall FlawPRO, exit the program, and select Start. Click on Programsand select FlawPRO. In the sub-list, clickonce on the Uninstallicon and follow the instructions that appear on the screen. You must confirm that you want to removeFlawPRO and all its components from your hard disk. Note that files of the type *.flpare not automatically removed by theUninstall program.


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Registering Your Copy of FlawPRO

In order to use FlawPRO as an analysis tool you must register your copy. If you are only reviewing or evaluating thisproduct, the DEMO MODE option is sufficient. In DEMO MODE your FlawPRO window will appear as follows:

Registration is a two-part process. First you provide information about yourself in an email message to FlawPROsadministrators. In return you receive a registration code that turns on the analysis features of FlawPRO.

To create the email message with your information, perform the following steps:

1. After launching FlawPRO, click on Help > About.

2. The About Box appears; click on the Registerbutton in the middle of the About Box.

3. The FlawPRO V3.x.x Registrationdialog box appears.

4. Complete the form. You must provide:

a. First nameb. Last Namec. Companyd. Phone Numbere. Complete Addressf. Email address


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5. Click on the Copy Registration. . .button at the bottom of the dialog.

6. Now open a mail message form in your email application and copy your registration data into the body of theemail. Address the email to Registration Email given at top of the FlawPRO V3.x.x Registration dialog box.

7. A registration code will be sent back to you by email at the address you provided.

To complete the registration process after receiving your registration code, follow these steps:

1. Open the email with the code and highlight it. Be sure to highlight only the code and not any leading or trailingblanks or other characters.

2. Copy the code to the clipboard.

3. Launch FlawPRO, click on Help > About.

4. The About Box appears; click on the Registerbutton in the middle of the About Box.

5. Paste from the clipboard to the Registration Codetext box the code you received.

6. Click the OK button. The FlawPRO Main form should now look like this.


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Setting Units in FlawPRO

1. English or metric units may be used.

2. Unit selection is done on the Analysis VariablesInput Screen.

3. Once unit selection is made, the unit setis "consistent" and will carry over to all input screens.

4. To change the unit selection, you must go back to the Analysis VariablesInput Screen and select the otherunit set.

Change Request and Error Report Form

Use this form to create an email report. To create an email report, highlight the text below and use the Copy command toput it on the Windows Clipboard. Open a blank email message form and paste the text into it. Answer the questions andemail it to the address given at the bottom of this form. Attach to the email any helpful data that may help duplicate theproblem, such as a scenario file(s) of the form *.flp.

For use by technical support staff only:#__________RD__________FD__________ND__________

Name: _______________________________________Phone Number: _________________________________

Date: ______________________________________

Program Version & Version Date: ________________ ____________(Available on the Aboutscreen at the beginning of the program or under Help > Aboutmenu item)___Windows XP ___Other (specify) _________


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Report Type: __ Error Report __ Change Request

__Other________________________________

Can Error Be Duplicated? __ Yes __ No __ NAPlease record text of any user messages given by the program or by Windows OS:

User Message Index ___________, Module Sourcing User Message__________________

Please describe your actions preceding the error OR describe the requested change:(Provide a quick review of actions since you started the current FlawPRO session and then detail the last few actions.)

Use additional lines if necessary. Deliver this completed form to: [email protected]

NomenclatureBoldNon-ItalicTypeis used to indicate menus, their sub-menus and commands as well as command button names.Examples: View > Optionsmenu command or the Plot JR Curvecommand button.

Bold Ital ic Typeis used to specify FlawPRO window or dialog box titles. Example: Geometrywindow.

Italic Typeis used to indicate any type of input that the user has control over in the graphical user interface of FlawPRO orany miscellaneous feature found on the inputs portion of the window. Example: Dependent Variable drop down list, or theCrack Transitioninggroup of inputs.

Bold blue textis used for sub-headings in the help topic to help you locate the relevant text.

Underlined green textis used to delineate jumps or links from the current topic to another topic in the help facility.

Green text with a dashed underlineis used to delineate glossary items. Click on this text and the definition of the word(s)appears in a pop up window.

View Menu: Viewing FlawPRO Input Screens

There are two ways to access the FlawPRO input screens. You can click Viewon the menu bar and then click the inputscreen you need or you can click directly on the applicable tool bar button. The tool bar appears underneath the menu bar.The tool bar has a button for each of the five input screens.

Help Menu: Using FlawPRO's On-line Help

1. Open the online help files by selecting Help > Contentsor Help > Relevant Topic from the menu. TheFlawPRO On-Line Help Facil itydialog will be displayed.

2. The Contentstab at the upper left corner of the left side of the dialog lists all the topics, by titles, which areincluded in help. A book icon indicates that there are sub-topics under that heading; click File > Opento viewthe list of topics. A page icon indicates an individual help topic. Highlight the desired topic and click on it to seeit. Click the Printbutton at the top of the dialog to print out a topic.

3. The Indextab shows an alphabetical listing of keywords which are in the help file. In the empty text box at thetop of theIndex tab type in the first few letters of the subject for which you need help, then select a topic todisplay.

4. The Search taballows you to search for specific words and phrases in a help file. A database is createdcontaining all the words in the file. The search capability can be minimized, maximized, or customized by theuser. Follow the instructions in the Find Setup Wizarddialog box to set up the database of help content the

first time.

5. In addition, this help file contains "Whats This" help, where information is directly available about manyindividual screen functions and inputs. Click on the Whats This menu item or the Whats Thisbutton and thenclick the screen item for which you want more information. A short topic will pop up onscreen; click off thepopup to close the topic.
mailto:[email protected]:[email protected]


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ANALYSIS FILE OPERATIONS

Creating A New Analysis File

You can create a new analysis file at any time.

1. In the FlawPRO Mainwindow, choose File > New Analysisfrom the menu bar.

2. If you have changed the current analysis file, you will be asked to save the existing scenario. Click on theYesor Nobuttons to indicate your response to the message box that appears.

3. FlawPRO re-configures itself for a new analysis. Begin by selecting the Analysis Options screen, followed bythe Variables, Geometry, Material and Loading screens.

Opening An Existing Analysis File

To open an analysis file that has been previously defined, follow these steps.

1. In the FlawPRO Mainwindow, choose File > Open Analysisfrom the menu bar.

2. The Select FlawPRO Scenario Filedialog box appears. Browse around your system until you find the folderand filename of the existing analysis file. The default folder for all analysis files is \FlawPRO\Scenarios\.

3. Highlight the filename of the analysis file you want by clicking on it. The name should appear in the File nametext box at the bottom of the form.

4. Click the Openbutton. The FlawPRO Mainwindow reappears, but now the title bar at the top of the windowindicates the path and name of the analysis file you selected. You may be asked to save the analysis you areabout to overwrite beforehand. Click on theYes or Nobuttons to indicate your response to the message boxthat appears.

Saving Or Copying An Analysis File

1. In the FlawPRO Mainwindow, choose File > Save Analysisor File > Save Analysis Asfrom the menu bar.

2. You may save your current analysis file at any time with Save Analysiscommand. All current inputs aresaved to the current file name (shown on the Mainwindow title bar).

3. If you wish to copy the current analysis or save your current work under a different file name, use the SaveAnalysis Ascommand. When you select this menu item, the Save File Asdialog box appears. Browsearound your system until you find the folder where you want to put your copy of the current analysis. Thedefault folder is \FlawPRO\Scenarios\.

4. In the File nametext box at the bottom of the dialog form, type in your new analysis file name. The defaultname for your copy is the current analysis files name.

5. Click the Savebutton.


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GRID AND PLOT PROCEDURES

Deleting A Row From The Grid

The Geom etry, Material and Loadinput screens have grids that are generated based on the information that has beeninput. Rows can be deleted from the grid by pressing on the Delete Rowbutton.

1. Using your mouse, click on the row you wish to delete. The black arrowhead that appears on the left-hand sideof the grid will move to that row and the row will be highlighted.

2. Press theDelete Rowbutton.

3. A pop-up box will appear asking if you want to delete a row.

4. If you pressYesthe entire row that is highlighted will be deleted.

5. Repeat this procedure for every row you wish to have deleted.

Adding Row To Grid

The Geom etry, Material and Loadinput screens have grids that are generated based on the information that has beeninput. Additional blank rows can be added to these grids by pressing the "Add Row" button next to the grid. Each click of

the "Add Row" button adds another blank row to the grid. The last row of the grid is marked by an.

Deleting All Rows From The Grid

The Geom etry, Material and Loadinput screens have grids that are generated based on the information that has beeninput. All the rows of data can be deleted from the grid by pressing on the Delete All Rowsbutton.

1. Using your mouse, click on the Delete All Rowsbutton.

2. A pop-up box will appear asking if you want to delete ALL rows.

3. If you pressYesthe entire data grid values will be deleted.

Importing Data From A File

1. Data can be imported from files into the data grids in the Geom etry, Materialand Load ingwindows. In thebottom of the Geometrywindow, find the Initial Crack Size Distributiongrid. A default set of initial crack heightand length values may be shown in the grid. (In the Materialwindow, a default set of stress-strain data areshown while In the Loadingwindow, a default set of minimum and maximum stresses and cycles are shownas well as tables containing default values for the normalized stress variations.)

2. Click once on the Import From Filebutton to the left of the grid. The Select Filedialog box appears. Browsearound until you find the folder containing the initial crack size distribution file (or stress-strain file or loadspectrum file or normalized stress variation file) that you want to import. Highlight the file name and click onthe Openbutton at the bottom right of the dialog box.

3. The distribution data will be imported into the existing grid. If you already have data in the grid, the importeddata will be appended to the existing grid data. If you have no data (blank rows) then the imported data will beimported and the blank rows deleted.

4. The distribution file you import can be in space-delimited, tab-delimited, or comma-delimited format and shouldcontain the distributions Crack Height, and Crack Length..ASample file, Flaw Size Table.txt, was installed inthe \FlawPRO \Scenarios\ directory. (Sample files for use with the Materialscreen (Stress Strain Table.txt)and Loadingscreen (Load Spectrum Table.txt and Normalized Stress Table.txt), were installed in the\FlawPRO \Scenarios\ directory.) Note that the aspect ratio values that appear in the Initial Crack SizeDistribution grid are calculated quantities and should not be entered as part of the data.


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5. To add additional rows of initial crack size (or in any other table), click the Add Rowbutton once. Additionalrows are always added at the bottom of the grid. Click once in any cell of the new row and start typing data.You must type the Crack Heightand Crack Length. The Crack Aspect Ratiocannot be input; it is a computedvalue.

Exporting Grid Data To A File

You can re-use crack size distributions or stress-strain data or service spectrum or normalized stress variations that youcreate in one scenario analysis in other analyses by exporting the distribution data. As an example, consider the crack sizedistribution.

1. Complete the Initial Crack Size Distributiongrid in the lower portion of the Geometrywindow.

2. Click once on the Export to Filebutton to the left of the grid. The Save File Asdialog box appears.

3. Browse until you find the folder in which you want to save the current scenarios initial crack size distribution.Type in the File nameinput box the name of the file and click the Savebutton.

4. Your crack size distribution data will be saved as a three-column tab-delimited text file.

Export Plot

1. Click on the Export Plotbutton.

2. A pop-up box will appear giving you five export file choices for your plot: Metafile, BMP, JPG, PNG, and"Text/Data only."

3. Based on your selection, further options are enabled or disabled.

4. Clicking the "Help" button that appears in the bottom right-hand corner of the pop-up box will provide additional,more detailed information on exporting your graph.

Print Plot

1. Click on the Print Plotbutton.

2. A pop-up box will appear showing the default printer, the current print orientation, and the paper bin.

3. You can select another printer via the dropdown combo box that will display all available system and networkprinters.

4. The printer orientation, paper bin, and other printer options can be adjusted by pressing the setup button toinvoke the printers setup dialog.

5. Pressing the "Help" button that appears in the bottom right-hand corner of the pop-up box will provideadditional, more detailed information on printing your graph.


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ENGINEERING CAPABILITIES AND LIMITATIONS

FlawPRO will enable the practicing engineer to assess the effects of service loading and pre-service reeling on the lifetimesof welded pipes that may contain pre-existing flaws, such as crack-like defects, and are subjected to variable amplitudefatigue loading. The program is designed to facilitate sensitivity analyses in order to enable the effects of changes in inputparameters on the lifetimes of installed pipes to be readily determined. The results of calculations are displayed in chartand tabular form that can be easily exported and used in engineering reports.

FlawPRO addresses the effects of postulated pre-existing circumferential flaws on the service lives of pipes that have eitherbeen conventionally installed or installed after being welded on land and reeled onto a spool. In the case of pre-servicereeling, the program determines the amount of ductile tearing and low cycle fatigue crack growth that occurs from thereeling process. In addition, fatigue growth from cyclic loads experienced during installation as a pipe hangs overboardafter reeling (but before entering service) and is subjected to wave-induced loads is calculated.

The generation of residual stresses from reeling and straightening processes is included in a FlawPRO analysis as well asthe influence of welding residual stresses on the service life of conventionally installed pipes. The high strains produced byreeling will wipe out any weld residual stresses that are present prior to reeling and replace them by reeling residualstresses.

The effects of cladding on the inside surface of pipes can be included in engineering critical assessments (ECAs) performedusing FlawPRO. This aspect of the FlawPRO methodology is based on engineering judgment but has not been validated.

There are nine analysis options in FlawPRO. In four of the analysis options

Option 1 (Service Fatigue Life) Option 3 (Critical Crack Size: Worst Case Service Load) Option 5 (Final Crack Size after Service fatigue) and Option 8 (Maximum Allowable Crack Sizes Service Fatigue)

the FlawPRO code can be applied without evidence that the pipe material is operating above the ductile-brittle toughnesstransition temperature (DBTTT). (Ferritic steels can fail by a brittle cleavage mechanism below the DBTTT withoutundergoing ductile tearing.) The remaining five analysis options

Option 2 (Service Life Following Pre-Service Reeling and Installation Fatigue) Option 4 (Reeling Life: Pre-Service Reels) Option 6 (Final Crack Size following Pre-Service Reeling, Installation Fatigue and Service Fatigue) Option 7 (Final Crack Size: Pre-Service Reeling) and Option 9 (Maximum Allowable Flaw Sizes: Pre-Service Reeling, Installation Fatigue and Service Fatigue)

should only be applied to assessments of ductile materials operating above the DBTTT that fail after undergoing some

degree of tearing.The FlawPRO code contains advanced elastic-plastic f racture mechanics (EFFM). These aspects include the estimationschemes employed to evaluate the effects of reeling on the elastic-plastic crack tip driving force, J, and the cyclic change inthis quantity during load cycling from reeling and straightening, !J. The effect of crack closure on fatigue crack propagationrates is allowed for in FlawPRO under reeling conditions only. (Crack closure can occur when the two surfaces of a crackcome together under compressive stressing, as occurs during reeling.)

Crack transitioning is allowed in FlawPRO. A crack transitions when one of its tips intercepts with a free surface and thecrack undergoes a change in its geometry as it continues to grow. For example, a surface flaw can grow through the wall ofa pipe and transition into a through-wall crack. This flaw re-characterization feature in FlawPRO should only be used whenthe pipe material is ductile, as crack transitioning in brittle materials could be coincident with incipient unstable crackpropagation of the pipe leading to structural failure. The transition option is not available when crack sizes at the end ofservice are being calculated.

Crack transitioning can involve a change in crack growth environment as well as a re-characterization of the flaw type. Inthe case of embedded flaws, FlawPRO allows for the possibility of different fatigue crack growth rates of a transitioned flaw

corresponding to different environments on the outside and inside of a pipe.

The methodology employed in the FlawPRO code has been quantitatively validated against full-scale test results formeasured lives of welded pipes containing flaws that have been subjected to reeling, simulated service fatigue loading, andreeling followed by simulated high cycle service fatigue.

The linear elastic fracture mechanics (LEFM) methodology employed to evaluate service lifetimes is similar to themethodologies that are employed in many other fatigue crack growth computer codes and procedures such as BS 7910.

The tear-fatigue methodology employed in FlawPRO to assess crack extension during reeling and straightening has beenvalidated against results obtained from full-scale cracked pipe tests. Flaw assessment procedures such as BS 7910 do notexplicitly address the high plastic straining conditions associated with the reeling of pipe that can result in flaw extension by


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tearing and low cycle fatigue (LCF). An attempt to address reeling is made in DNV report Recommended Practice DNV-RP-F108 titled Fracture Control for Pipeline Installation Methods Introducing Cyclic Plastic Strain. The assessmentmethodology under-pinning DNV-RP-F108 differs from the methodology incorporated into FlawPRO. DNV-RP-F108 treatsthe effects of reeling on flaw growth as if it was two tearing events that can be addressed by two independent applications ofBS 7910 Level 3B to evaluate the amount of tearing arising from each event. This approach ignores both the historydependent interaction between the two tearing events and the effects of the LCF cycle that occurs during reeling. The tear-fatigue model included in FlawPRO takes full account of these phenomena and has been validated against the results offull-scale and small-scale tests simulating cyclic plastic straining.

The full-scale validation test results used to validate FlawPRO for reeling followed by service loading showed no significantoverload effects on service crack growth resulting from pipe reeling and straightening. (Under some circumstances, it hasbeen observed that overloads can result in retarded crack growth rates in steels compared with the rates that would haveoccurred without the overload.)


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ANALYSIS OPTIONS SCREEN

The Analysis Opt ionsscreen must be completed first in order to begin your analysis.

1. Pressing on the Optionsbutton at the top of the screen or clicking View > Optionswill present you with ascreen organized into two categories: Analysis Optionsand either Crack Transitioningor Reeling History.

2. Crack Transitioningor Reeling Historyinput frames appear on the screen depending upon the analysis option

you choose.

3. Select one and only one of the 9 analysis options by darkening the circle to the left of the choice.

4. For Analysis Options 1, 2, 4, 8, and 9, you may indicate whether you wish to allow crack transitioning effects inyour analysis or not. Darken the circle to the left of Crack Transitioningif you wish to include such effects.

5. If you select option 3, you can indicate whether or not you wish to include effects from prior reels in theanalysis. If you wish to include such effects, darken the circle to the left of Residual Stress Present Due toReeling.

6. For analysis types 5 through 7, neither crack transitioning nor reeling history effects are available as ananalysis option.

After completing the Analysis Opt ionsscreen, you should then move on to the Variablesscreen.


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VARIABLES SCREEN

Setting Up Sensitivity Analysis Variables

You must specify the independent and dependent variables in your analysis after you have selected the analysis options.

1. Open the Variables window by choosing either View > Sensitivity Analysis Variablesin the menu bar or

clicking on the Variablesbutton in the tool bar.

2. Select the Primary Independent Variable (PIV) for the current analysis by clicking on the self-titled drop downlist at the bottom of the window.

3. Select the Secondary Independent Variable (SIV) for the current analysis by clicking on the self-titled dropdown list at the top of the window. You are not required to have an SIV. If you choose an SIV that is the sameas the previously selected PIV, you must re-select your PIV and vice versa.

4. Select the Dependent Variable for your analysis. Generally speaking, only one DV is available.

If you selected Analysis Options 1, 2, or 4 (Service or Reeling Life) on the Ana lys is Opt ionsscreen,then the Dependent Variable will automatically be Lifetime or Reeling Life.

If you selected Analysis Option 3 (Critical Crack Size) on the Ana lys is Opt ionsscreen, then theDependent Variable will automatically be Critical Crack.

If you selected Analysis Options 5, 6, or 7 (Final Crack Size) on the Analysis Opt ionsscreen, then theDependent Variable will automatically be Final Crack Size.

If you selected Analysis Options 8, or 9 (Maximum Allowable Initial Flaw Sizes) on the AnalysisOpt ionsscreen, then the Dependent Variable will automatically beAllowable Crack Size.

5. Choose the Unit Set for This Analysisby clicking on the drop down list in the upper left hand corner of thewindow. You may choose your units at any time during the input process by returning to the Variableswindowand choosing a new unit set from this drop down list. FlawPRO automatically converts data specified in oneunit set into the other unit set if the unit set is changed.


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Establishing the Range of Primary Independent Variables (PIV)

Once you have selected which analysis variable is to be the PIV, then the input for that variable is replaced with a Primarybutton. This button controls a pop-up form that allows you to indicate the PIV range (minimum and maximum values of thevariable) and the steps within that range where results are to be calculated. FlawPRO will automatically compute DV valuesfor PIV values that fall within the specified range.

1. When you open the form containing the PIV input, click on the Primarybutton.

2. A pop-up screen will appear with spaces to type in minimum and maximum values.

3. Type in your values and enter the number of steps in the range where you want results calculated. Click on OKwhen you are finished.

4. Your min/max values are now set for your PIV. Should you wish to change them, you will need to come back tothis screen and re-input them.

Example:

If Service Toughnessis chosen as the Primary Independent Variables(PIV) on the Variables screen when Option 2 isselected, then the Material(Service Fatigue) screen will have a button marked Primarynext to the input label Toughnessinthe Material Dataframe. Click on this button and enter example PIV values, such as those shown in the figure below.


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Defining Discrete Values for Secondary Independent Variables (SIV)

Once you have selected which analysis variable is to be the SIV, then the input for that variable is replaced with aSecondarybutton. This button controls a pop-up form that allows you to indicate up to eight discrete SIV values.

1. When you open the form containing the SIV input, click on the Secondary button.

2. A pop-up screen will appear with input boxes in which you type in discrete values. You must enter at least onevalue, but you need not provide all eight. SIV values can be entered in any order.

3. Type in your values and click on OK when you are finished. Use the Insert and Delete buttons to re-arrangeyour discrete values.

4. Your discrete values are now set for your SIV. Should you wish to change them, you will need to come back tothis screen and re-input them.

Example:

If Service Toughnessis chosen as the Secondary Independent Variables(SIV) on the Variables screen when Option 2 isselected, then the Material(Service Fatigue) screen will have a button marked Secondarynext to the input labelToughnessin the Material Dataframe. Click on this button and enter example SIV values, such as those shown in thefigure below.


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GEOMETRY SCREEN (Unclad Pipe)

Defining Pipe and Crack Geometry (Unclad Pipe)

To define Pipe Dimensionson the Geometryscreen:

1. Key in the Outside Diameter, OD, and

2. key in the pipes Wall Thickness, t.

To define Crack Locationson the Geometryscreen:

1. Select one of the four choices for your crack location. The drawing on the right-hand side of the screen willillustrate your crack location selection.

2. If you choose Embedded in Wallas your crack location, then you will need to fill in the Offset ybox. Look atthe drawing on the right-hand side of the screen for the definition of this dimension.


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Defining Initial Crack Size Distribution (Unclad Pipe)

You may type initial crack size values, or import them from a file of the correct format.

Typing Initial Crack Size Values

1. In the bottom of the Geometrywindow, find the Initial Crack Size Distribution grid. Default initial crack heightsand lengths may be shown in the grid.

2. You can accept the defaults, delete the default rows, or type over the defaults with new data. To accept thedefault data rows, do nothing. To delete the default rows, click once on any cell in the default data row andthen click on the Deletebutton to the left of the grid, or use the Delete All Rowsbutton to delete all values inthe grid. To type over the default data, click once on any cell in row. The entire cell contents should behighlighted. Start typing your new data.

3. To add additional rows of initial crack size data, click the Add Rowbutton once. Additional rows are alwaysadded at the bottom of the grid. Click once in any cell of the new row and start typing data. You must type theCrack Height andCrack Length. The Crack Aspect Ratiocannot be input; it is a computed value. You mayhave up to 200 rows of crack size data.

Importing Initial Crack Size Values From A File

To import data from a text file (often created by using the Exporting Initial Crack Size Distributions feature), follow thesesteps:

1. In the bottom of the Geometrywindow, find the Initial Crack Size Distributiongrid. Default initial crack heightsand lengths may be shown in the grid.

2. Click once on the Import FromFile button to the left of the grid. The Select Filedialog box appears. Browsearound until you find the folder containing the initial crack size distribution file that you want to import. Highlightthe file name and click on the Openbutton at the bottom right of the dialog box.


4. The distribution file you import must be in space-delimited, tab-delimited, or comma-delimited format andcontain the distributions Crack Heightand Crack Length(it can also contain the aspect ratio, but his will be re-calculated by the program). A sample crack size file, Flaw Size Table.txt, was installed in the\FlawPRO\Scenarios\ directory

5. To add additional rows of initial crack size data, click the Add Rowbutton once. Additional rows are alwaysadded at the bottom of the grid. Click once in any cell of the new row and start typing data. You must type theCrack Heightand Crack Length. The Crack Aspect Ratiocannot be input; it is a computed value.


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Exporting Initial Crack Size Distributions (Unclad Pipe)

You can re-use crack size distributions that you create in one scenario analysis in other analyses by exporting thedistribution data.

1. Complete the Initial Crack Size Distribution grid in the lower portion of the Geometrywindow.



4. Your crack size distribution data will be saved as a three-column, tab-delimited, text file.


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Plotting Initial Crack Height Versus Length Distributions (Unclad Pipe)

1. On the Geometrywindow, find the Initial Crack Size Distributiongrid and provide distribution data.

2. Click once on the Plot h-Lbutton in the upper middle area of the window. The Plotwindow appears showingthe Initial Crack Size Distributiongraph.

3. This graph shows each unique combination of initial crack size height (h) and length (L) and typically has a

stair-step appearance.

4. Use the Export Plot, Print Plot and Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) or a file, the printer, or to return to theGeometryscreen.


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GEOMETRY SCREEN (Clad Pipe)

Defining Pipe and Crack Geometry (Clad Pipe)

To define Pipe Dimensionson the Geometryscreen:

1. Key in the Outside Diameter, OD, and

2. Key in the pipes Wall Thickness, t.

To define Inside Surface Clad Dimensionson the Geometryscreen:

1. Select the Clad Pipeoption by clicking on the circle to the left. This enables the Clad Thicknesstext box.

2. In the Clad Thicknesstext box provide the thickness of the pipe's cladding.

To define Crack Locationson the Geometryscreen:

1. Select one of the four choices for your crack location. The drawing on the right-hand side of the screen willillustrate your crack location selection.

2. If you choose Embedded in Wallas your crack location, then you will need to fill in the Offset ybox. Look at the

drawing on the right-hand side of the screen for the definition of this dimension.


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Defining Initial Crack Size Distribution (Clad Pipe)

You may type initial crack size values, or import them from a file of the correct format.

Typing Initial Crack Size Values

1. In the bottom of the Geometrywindow, find the Initial Crack Size Distribution grid. Default initial crack heightsand lengths may be shown in the grid.

2. You can accept the defaults, delete the default rows, or type over the defaults with new data. To accept thedefault data rows, do nothing. To delete the default rows, click once on any cell in the default data row and thenclick on the Deletebutton to the left of the grid, or use the Delete All Rowsbutton to delete all values in thegrid. To type over the default data, click once on any cell in row. The entire cell contents should be highlighted.Start typing your new data.

3. To add additional rows of initial crack size data, click the Add Rowbutton once. Additional rows are alwaysadded at the bottom of the grid. Click once in any cell of the new row and start typing data. You must type the Crack Height, andCrack Length. The crack'sAspect Ratiocannot be input; it is a computed value. You mayhave up to 200 rows of crack size data.

Importing Initial Crack Size Values From A File

To import data from a text file (often created by using the Exporting Initial Crack Size Distributionsfeature), follow thesesteps:

1. In the bottom of the Geometrywindow, find the Initial Crack Size Distributiongrid. Default initial crack heightsand lengths may be shown in the grid.

2. Click once on the Import FromFile button to the left of the grid. The Select Filedialog box appears. Browsearound until you find the folder containing the initial crack size distribution file that you want to import. Highlightthe file name and click on the Openbutton at the bottom right of the dialog box.


4. The distribution file you import must be in space-delimited, tab-delimited, or comma-delimited format andcontain the distributions Crack Heightand Crack Length(it can also contain the aspect ratio, but his will be re-calculated by the program). A sample crack size file, Flaw Size Table.txt, was installed in the\FlawPRO\Scenarios\ directory.

5. To add additional rows of initial crack size data, click the Add Rowbutton once. Additional rows are alwaysadded at the bottom of the grid. Click once in any cell of the new row and start typing data. You must type theCrack Heightand Crack Length. The crack'sAspect Ratiocannot be input; it is a computed value.


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Exporting Initial Crack Size Distributions (Clad Pipe)

You can re-use crack size distributions that you create in one scenario analysis in other analyses by exporting thedistribution data.

1. Complete the Initial Crack Size Distribution grid in the lower portion of the Geometrywindow.



4. Your crack size distribution data will be saved as a three-column, tab-delimited, text file.


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Plotting Initial Crack Height Versus Length Distributions (Clad Pipe)

1. On the Geometrywindow, find the Initial Crack Size Distributiongrid and provide distribution data.

2. Click once on the Plot h-Lbutton in the upper middle area of the window. The Plotwindow appears showingthe Initial Crack Size Distributiongraph.

3. This graph shows each unique combination of initial crack size height (h) and length (L) and typically has astair-step appearance.

4. Use the Export Plot, Print Plotand Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) or a file, the printer, or to return to theGeometryscreen.


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MATERIALS SCREEN

Material Properties

You must provide material properties, such as strength, toughness, stress-strain relations, and fatigue constants for thethree operating regimes applicable to the pipe. These regimes are reeling, installation fatigue, and service fatigue.

In the case of unclad pipes, only the properties of the ferritic pipe material have to be specified. In the case of clad pipes,sets of material properties for both the ferritic and clad materials have to be specified.

Reeling and Installation (Ferritic Material)

Specifying Pipe Material Behavior for Reeling and Installation Fatigue (Ferritic Material)

To perform a FlawPRO analysis you must specify the pipes stress-strain behavior, toughness properties, and crack growthbehavior. The Materialwindow contains these inputs.

1. Open the Materialwindow by clicking on the Materialbutton on the tool bar or selecting View > MaterialPropertiesfrom the menu bar.

2. Find the Display Material Inputs frame at the top of the window, choose the Reeling Plus Installation Fatigue

data by darkening the circle to the left. If this circle was not already dark, the remainder of the Materialwindowwill now change.

3. Type in the toughness (including J-R-curve) data inputs appropriate for the Analysis Option you have selected.The J-R curve can be specified in either of two different ways, as a bilinear curve or as a power law curve.Click on the Plot JR Curvebutton to view the defined J-R curve.

4. Provide the Ramberg-Osgood equation constants or the tabular values of stress and plastic strain that definethe true stress-true strain curve of the material. The tabular form of the stress-plastic strain curve can beimported as data contained in an existing file. Click on thePlot True Stress-Strain Curve button to view thedefined stress-strain curve.

5. Type in the coefficient, C, and exponent, m, for the reeling fatigue Paris Law equation, Or click on the ChooseFrom Librarybutton to select fatigue law constants from a library of values for steel welds in variousenvironments derived from data given in BS 7910. Confirm your inputs by clicking on the Plot da/dN versusDelta Kbutton.

6. Provide threshold, low range, and high range parameters for up to three Paris crack growth equationsgoverning installation fatigue. You may obtain these values from a library of values for steel welds in variousenvironments derived from data given in BS 7910 by clicking on the Choose From Librarybutton. Two of thethree Paris equations are relevant only to embedded flaws that transition during fatigue growth to surface flawson either the outer or inner pipe surface and become exposed to the environments adjacent to these surfaces.

7. Click on the Plot da/dN versus Kto view the selected fatigue crack growth curves for each installationfatigue regime (up to three if an embedded flaw transitions to surface flaw on the inner or outer pipe wallsurfaces) to confirm the crack growth behavior is what you want for this analysis.


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Defining Pipe Weld Strength and Fracture Properties for Installation and Reeling Fatigue (Ferritic Material)

In FlawPRO, weld material properties are fundamental strength of materials and fracture mechanics properties necessary

for analysis.1. In the Materialwindow, find the Material Datainput frame in the upper left hand corner of the window.

2. Provide the materials mechanical properties: Yield Stress, Ultimate Stress, Elastic Modulus, and PoissonsRatio; and the fracture mechanics data: Toughnessand Saturation Tear Length. Note that detailed strain-strain behavior has to be specified in the True Stress - Strain Definition input frame.

3. Most of these inputs are constants for all types of FlawPRO analysis, but a few, such as material Toughness,may be selected as either primary or secondary input variables. In this circumstance you must provide multiplevalues for the input.

4. Find the JR-Curveinput frame.

5. Establish the ductile tearing properties of the pipe by providing parameters for the JR-Curve, such as the CurveSlope, if you adopt a Bilinearform; or the Coefficient and Exponentif you adopt a Power Lawform.

6. Click on the Plot the JR Curve button to review the effect of your inputs on the ductile resistance to crackgrowth.


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Plotting The JR Curve (Ferritic Material)

The JR-curve characterizes a materials resistance to ductile tearing and is a measure of its toughness.

1. On the Materialwindow, find the Material Data input frame. Complete all the inputs even though some of thedata are not necessary for the JR curve calculation.

2. At the bottom of the Material Data input group, click once on the Plot JR Curve button. The Plotwindowappears, showing the JR Curve graph for your material inputs.

3. Use the Export Plot, Print Plot and Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) or a file, the printer, or to return to the Materialscreen.


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Defining and Plotting The True Stress-Strain Relationship for Reeling and Installation (Ferritic Material)

FlawPRO provides two means to specify the true stress-true strain behavior of the welded pipe, either via a Ramberg-Osgood equation or via a table of true stress versus true plastic strain values.:

Ramberg-Osgood Model

1. Find the True Stress Strain Definitioninput frame in the Materialwindow.

2. Select the Ramberg-Osgood Equation: Constantsby clicking on the circle to the left.

3. Provide the Coefficient () , the Yield (!o) and Exponent (n) by typing values in the labeled text boxes. These

terms appear in the Ramberg-Osgood equation:

n

o

o

EE

+=

.

True Stress Plastic Strain Table


2. Select the Tabular Valuesmethod by clicking on the circle to the left.

3. Use Add Row, Delete Row, orImport From Filebuttons to put true Stressand Plastic Straindata in the tableprovided.

Plotting

1. You can check the stress-strain relationship you specified by plotting it. Click on the Plot True Stress StrainCurvebutton.

2. The stress versus strain relation appears in the displayed graph.


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3. Use the Export Plot, Print Plot and Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) a file, the printer, or to return to the Materialscreen.

TIP: If you import your data from a file, the stress-strain pairs should be separated by a delimiter: tab, comma, or space;tabs are preferred.

TIP: You should organize your stress-strain data so that strain and strain increase monotonically from the top to thebottom of the table.

TIP: The number of tabular entries is limited to a maximum of 100 data pairs.

Defining Reeling Fatigue: Paris Equation Constants (Ferritic Material)

In FlawPRO, you provide constants for the Paris Equation to account for low cycle fatigue due to the reeling history.

1. In the Materialwindow, find the Display Material Inputs frameat the top of the window and choose the ReelingPlus Installation Fatiguedata by darkening the circle to the left. If this circle was not already dark, theremainder of the Materialwindow will now change.

2. Find the Reeling Fatigue Constantsinput frame in the upper right portion of the window.


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3. Decide if you want to choose fatigue constants from the library or provide your own parameters for this analysis.

4. To select your parameters from the library,

a. Click on the Choose From Library button. The Fat igue Librarydialog box appears.

b. Choose a material / environment and click the OKbutton, or simply double-click on a material /environment item in the list. Fatigue law parameters will automatically be filled in.

5. To input your own fatigue constants, you must provide the coefficient, C,and exponent, m,in accordance with

the Paris equation form mKC

d

da = .

6. If you wish to plot the variation in da/dN with !K for these inputs, click on the Plot da/dN versus Delta Kbutton.


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3. For each set of fatigue law parameters to be input, decide if you want to choose from the library of fatigueconstants or provide your own parameters for this analysis.

4. To select your parameters from the library,

a. Click on the Choose From Library button. The Fat igue Librarydialog box appears.

b. Choose a material / environment and click the OKbutton, or simply double-click on a material /environment item in the list. Fatigue law parameters will automatically be filled in.


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5. To specify the fatigue constants yourself, you must provide the coefficient, C,and exponent, m,in accordance

with the Paris equation form mKC

d

da = .

6. If you wish to plot the variation in da/dN with !K for these inputs, click on the Plot da/dN versus Delta Kbutton.

Plotting Installation Fatigue Paris Equations (Ferritic Material)

The Paris equation characterizes the crack growth rate per cycle in terms of the cyclic change in the stress intensity factorbetween the maximum and minimum cycle.

1. On the Materialwindow, find the Installation Fatigue Constants input frame. Complete all the inputs.

2. At the bottom of the Installation Fatigue Constants input frame, click once on the Plot da/dN versus Delta Kbutton. The Plotwindow appears, showing the Installation Fatigue Growth graph for your Paris Equationinputs.

Use the Export Plot, Print Plot and Closebuttons at the bottom of the graph to either send your data to the clipboard (forimport in other Windows-compatible application) a file, the printer, or to return to the Materialscreen.


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Plotting The JR Curve (Clad Material)

The JR-curve characterizes a materials resistance to ductile tearing and is a measure of its toughness.

1. On the Materialwindow, find the Material Data input frame. Complete all the inputs even though some of thedata are not necessary for the JR curve calculation.

2. At the bottom of the Material Data input group, click once on the Plot JR Curvebutton. The Plotwindow

appears, showing the JR Curve graph for your material inputs.

3. Use the Export Plot, Print Plotand Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) or a file, the printer, or to return to the Materialscreen.


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Defining and Plotting The True Stress-Strain Relationship for Reeling and Installation (Clad Material)

FlawPro provides two means to specify the true stress-true strain behavior of the welded pipe,either via a Ramberg-Osgood equation or via a table of true stress versus true plastic strain values.

Ramberg-Osgood Model

1. Find the True Stress Strain Definition input frame in the Materialwindow.

2. Select the Ramberg-Osgood Equation: Constantsby clicking on the circle to the left.

3. Provide the Coefficient (), the Yield (!o) and Exponent (n) by typing values in the labeled text boxes. Theseterms appear in the Ramberg-Osgood equation:

n

o

o

EE

+=

True Stress Plastic Strain Table


2. Select the Tabular Valuesmethod by clicking on the circle to the left.

3. Use Add Row, Delete Row, orImport From Filebuttons to put true Stressand Plastic Straindata in the tableprovided.

Plotting

1. You can check the stress-strain relationship you specified by plotting it. Click on the Plot True Stress StrainCurvebutton.

2. The stress versus strain relation appears in the displayed graph.

3. Use the Export Plot, Print Plotand Closebuttons at the bottom of the graph to either send your data to theclipboard (for import in other Windows-compatible application) a file, the printer, or to return to the Materialscreen.


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TIP: If you import your data from a file, the stress-strain pairs should be separated by a delimiter: tab, comma, or space;tabs are preferred.

TIP: You should organize your stress-strain data so that strain and strain increase monotonically from the top to the bottomof the table.

TIP: The number of tabular entries is limited to a maximum of 100 data pairs.


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Defining Reeling Fatigue: Paris Equation Constants (Clad Material)

In FlawPRO, you provide constants for the Paris Equation to account for low cycle fatigue due to the reeling history.

1. In the Materialwindow, find the Display Material Inputs frame at the top of the window and choose the Reelingplus Installation Fatigue (Clad)data by darkening the circle to the left. If this circle was not already dark, theremainder of the Materialwindow will now change.

2. Find the Reeling Fatigue Const

Documents

FlawPro usermanual03_09