AUTOPIPE
©
TUTORIAL: ISO 14692 - FIBER REINFORCED PLASTIC PIPING CODE
Written by: Joshua Taylor Revision: 0 Last updated: 28 January, 2014
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Bentley Systems, Incorporated 685 Stockton Drive Exton, PA 19341, United States +1 610-458-5000 www.bentley.com © 2014, Bentley Systems, Incorporated. All Rights Reserved. Bentley, the "B" Bentley logo, MicroStation, ProjectWise, AutoPLANT and AutoPIPE are registered or nonregistered trademarks of Bentley Systems, Inc. or Bentley Software, Inc. All other marks are the property of their respective owners. AutoPIPE online resources: Product information: http://www.bentle http://www.bentley.com/en-US/ y.com/en-US/Products/Bentl Products/Bentley+AutoPIPE ey+AutoPIPE// Pipe stress & vessel design forum: http://comm http://communities.bentley.co unities.bentley.com/products/pipe m/products/pipe_stress_analysis/f _stress_analysis/f/275801.a /275801.aspx spx SELECT services: http://selectservices.bentley.com/en-US/
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TABLE OF CONTENTS 1
Introduction ............................................................................................................................ ......................................................................................................................................................... ............................. 1 1.1
Feature Overview ......................... ...................................... .......................... .......................... .......................... .......................... .......................... .......................... ......................... ........................ ............1
1.2
About this tutorial .......................... ....................................... .......................... .......................... ......................... .......................... .......................... ......................... .......................... ....................... .......... 1
1.3
Associated files .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... ............... 1
2
Workflow Overview ................................................................ ............................................................................................................ .............................................................................. .................................. 2
3
Model Overview .......................................................................................... ..................................................................................................................................... ......................................................... .............. 3
4
Model Setup ........................................................................ .................................................................................................................... ................................................................................. ..................................... 5
5
Model Geometry ............................................................................................................... .................................................................................................................................................. ................................... 6 5.1
Defining Pipe Properties..................................... .................................................. .......................... .......................... .......................... .......................... .......................... .......................... ............... .. 6
5.2
Define Operating Conditions .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... ................... ...... 8
5.3
Defining Bend Points .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... .................. ..... 9
5.4
Defining Tee Points .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... .................. ..... 10
6
Special Considerations ...................................................... ................................................................................................. .................................................................................. ....................................... 12 6.1
7
Loading ......................................... ..................................................................................... ........................................................................................ ......................................................................... ............................. 14 7.1
8
Define an Earthquake Load .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... ................... ......14 Analysis ................................................................................................... ............................................................................................................................................... ........................................................... ............... 15
8.1
Run Analysis .......................... ...................................... .......................... ........................... ......................... ......................... .......................... .......................... .......................... .......................... ................. .... 15
8.2
Allowable Calculations .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... .............16
9
Post Processing ............................................... ........................................................................................... ........................................................................................ ........................................................ ............ 20 9.1
Defining Load Combinations .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... ................. .... 20
9.2
Setting Model Result Options .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... ............... ..21
10
Defining a Joint Type .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .......................... .......................... ................ ... 12
Results .......................................... ...................................................................................... ........................................................................................ ......................................................................... ............................. 22
10.1
Generate Output Report ......................... ...................................... .......................... .......................... .......................... .......................... .......................... .......................... ..................... ........ 22
10.2
View Code Stress Color Plots..................... Plots.................................. .......................... .......................... .......................... .......................... .......................... .......................... ................... ......26
10.3
View Code Stress on the Result Grid ..................... .................................. .......................... .......................... .......................... ......................... ......................... ..................... ........ 28
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11 11.1 Quiz
Result Comparison.............................................................................................................................................. 29 Comparing AutoPIPE results with Supplied Output File.............................................................................29 30
Solutions............................................................................................................................................................................ 1
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1
INTRODUCTION
1.1
FEATURE OVERVIEW
ISO 14692, introduced as a Fiber Reinforced Plastic (FRP) piping code in AutoPIPE 9.5.0, is an international standard dealing with the qualification of joints and pipes for certain applications. It describes how to qualify and manufacture GRP/GRE (Glass Reinforced Epoxy) pipe and fittings, how to conduct system design and guidelines for fabrication, installation and operation.
1.2
ABOUT THIS TUTORIAL
This tutorial is intended towards users having adequate experience of AutoPIPE modeling and analysis. After completing this tutorial you will be able to understand modeling features provided by AutoPIPE for FRP piping, understand analysis options, result options and default combinations provided by AutoPIPE in regards to ISO 14692. The approximate time required for running this tutorial is two (02) hours. This tutorial is intended to be used with AutoPIPE version 9.6.0. The menu options and dialog controls in this tutorial are displayed in Green Italic. Additional notes and tips are displayed in Blue Italics.
1.3
ASSOCIATED FILES
The following files are provided at the locations mentioned below with this tutorial: [Install directory]\Examples\ISO_FRP_14692.DAT (Archived in the APC file) [Install directory]\Examples\ISO_FRP_14692.OUT
1 ISO 14692 FRP
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M o d e l S e t u p
D e f i n e M o d e l P r o p e r t i e s
D e f i n e S p e c i a l C o n s i d e r a t i o n s
D e f i n e a n o c c a s i o n a l l o a d
WORKFLOW OVERVIEW
Open a pre-existing ISO 14692 model and review General Model Options
Define Pipe Properties, Operating Conditions, Bend and Tee points
Define a Joint Type & User SIF at a bend
Define one static earthquake load for occasional combinations
2 ISO 14692 FRP
M o d e l A n a l y s i s
Define static analysis loads and analyze model
R e s u l t M o d e l O p t i o n s
Review options available in the Result Model Options dialog
M o d e l R e p o r t
Finally review the output report results, generate color plots for code stresses and review the results in the output grids
3
MODEL OVERVIEW
The model used in this tutorial is found at [install directory]\Examples\ISO_FRP_14692.APC . In order to access the model, un-archive the ISO_FRP_14692.APC file through File > Model Management > Open Archive , and select the ISO_FRP_14692.APC file. AutoPIPE will create a folder with the model name, and in this folder is the model itself. This is a simple model with pipe runs, tee component and bend.
3 ISO 14692 FRP
Note: Retaining the archive will keep a copy of the initial model for future use of this tutorial.
4 ISO 14692 FRP
4
MODEL SETUP
After launching AutoPIPE, click on File > Open to open the model (refer to section 3 for the directory and procedure to un-archive the APC file sent with the AutoPIPE installation). Save the model at a different location using File > Save As . Invoke the General Model Options dialog (Tools > Model Options > General ) and review the information in the table below on the General Model Options dialog:
Field
Comments
Piping Code
This is the ISO FRP code discussed in this tutorial
Edition
This is currently the only ISO 14692 edition for AutoPIPE
Unit file name - Input / Output
The default unit system for ISO 14692 is SI
Number of thermal/pressure cases
One pressure/ temperature case is considered for this tutorial. This is the ambient temperature defined for the model.
Ambient temperature
The cold modulus, and cold allowable will be fetched from the library at this temperature.
Libraries - Component Libraries - Material
This is the default component library for ISO 14692 code. This is the default material library for ISO 14692 code.
Press OK on the General Model Options dialog without any changes.
5 ISO 14692 FRP
5
MODEL GEOMETRY
In this part of the tutorial, we will review the current geometry for our model.
5.1
DEFINING PIPE PROPERTIES
After the General Model Options, open the Pipe Properties dialog for 20mmPIPE through Modify > Properties of Pipe Identifier :
Note the following fields specific to ISO 14692 on the Pipe properties dialog:
Field
Description
Schedule
This defines the piping schedule. For ISO FRP, this field is always disabled
Sigma al(0:1)
Long term axial stress at 0:1 stress ratio, MPa
Sigma al(2:1)
Long term axial stress at 2:1 stress ratio, MPa
6 ISO 14692 FRP
Sigma hl(2:1)=Qs
Long term hoop stress at 2:1 stress ratio, MPa
Sigma al(1:1)
Long term axial stress at 1:1 stress ratio, MPa
Sigma hl(1:1)
Long term hoop stress at 1:1 stress ratio, MPa
A2 Chem Resist
Partial factor for chemical resistance. Used to determine the allowable values
A3 Cyc. Service
Partial factor for cyclic service. Used to determine the allowable values
Press OK on the Pipe Properties dialog, and open the 15MMPIPE ID through Modify > Properties of Pipe Identifier :
Note: Currently the schedule field remains disabled for ISO 14692 and the Actual ID, and Wall thickness fields shall be manually updated. Note: Although the A2 Chem Resist and A3 Cyc. Service fields are defined in the Pipe Properties dialog, the A1 Temp. factor is defined in the Operating Pressure & Temperature.
7 ISO 14692 FRP
5.2
DEFINE OPERATING CONDITIONS
Select the entire model and open the Operating Pressure & Temperature dialog through Modify > Operating 2
2
Pressure & Temperature. Update the Pressure field from 1.00 N/mm to 5.00 N/mm .
The following fields relevant to ISO 14692 shall be noted:
Field
Temp. A1-fac.
Description
Temperature-dependent A1 factor, taken from the material library ISOGRPM. Used to determine the allowable values The default value for materials with specific gravity less than 0.2 would be 0.80
Temp. k-fac.
(gas). For a value of specific gravity greater than or equal to 0.2, the value would be set to 0.85. You can uncheck the Auto check box for this field and can then update this field to a user defined value.
Poisson Vmin
Temperature-dependent Poisson Vmin values, taken from the material library ISOGRPM
Update the Temperature field to 100°C. Note the warnings that display. Close the warning and change the temperature back to 50°C. Close the Operating Pressure & Temperature dialog by pressing OK . The Press/Temp/PipeID tab of the "Review Component Data" dialog can be used to modify the same values.
8 ISO 14692 FRP
5.3
DEFINING BEND POINTS
Select the bend point and open the Bend dialog by selecting Modify > Bend . Change the Biaxial Type from Filament—wound unidirectional to 100% hand-lay. Note the change made to the Biaxial Ratio –r field.
Note the following changes to the Bend dialog:
Field
Description
Qualified Stress
This field represents , from section 7.8
9 ISO 14692 FRP
Biaxial type
Biaxial Ratio –r
Qualified component
Bend component fitting type The ratio of the short-term axial strength under 0:1 stress ratio to the short-term hoop strength under 2:1 stress ratio Determines if the pressure at the component is qualified and set the pressure stress multiplier equal to 1.0
Press OK to close the Bend dialog.
5.4
DEFINING TEE POINTS
We will now review changes made to the tee dialog. Select A01 and open the tee dialog by selecting Modify > Tee .
Note the following changes to the Tee dialog:
Field
Description
Qualified Stress
This field represents , from section 7.8 10 ISO 14692 FRP
Biaxial Ratio –r
Qualified Component
Type of Tee
The ratio of the short-term axial strength under 0:1 stress ratio to the short-term hoop strength under 2:1 stress ratio Determines if the pressure at the component is qualified and set the pressure stress multiplier equal to 1.0 Define the type of tee. For ISO 14692, there are only Filament-wound and userdefined.
Close the tee dialog by pressing the OK button.
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6
SPECIAL CONSIDERATIONS
6.1
DEFINING A JOINT TYPE
To define a joint type on the A02 bend, select A02 N and open the Joint Type & User SIF dialog by selecting Insert > Xtra Data > Joint Type & User SIF . The following dialog displays:
Set the Joint End Type to Threaded. To enable the ISO 14692 fields, check the following boxes: •
Set qualified stress value
•
Set biaxial ratio value
•
Set pressure multiplier value
This enables the following fields
Field
Description
Qualified Stress
This field represents , from section 7.8
Biaxial Ratio –r
Pressure Multiplier
The ratio of the short-term axial strength under 0:1 stress ratio to the short-term hoop strength under 2:1 stress ratio Multiply the applied pressure to the joint
12 ISO 14692 FRP
Set qualified stress to 20, biaxial ratio as 0.45 and leave the qualified component under the pressure multiplier checked.
The Review Component Data grid reflects the Joint Type & User SIF addition.
13 ISO 14692 FRP
7 7.1
LOADING DEFINE AN EARTHQUAKE LOAD
To define an occasional load combination, we will introduce an earthquake load to the mode. Open the Static Earthquake dialog by selecting Load > Static Earthquake . Enter a new earthquake load, with the user factors of (1.0, 0.5, 1.0).
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8 8.1
ANALYSIS RUN ANALYSIS
We will now create a static load case, and run the analysis. Open the Static Analysis Load Cases by selecting Load > Static Analysis Sets, select the first analysis set and press the Modify button.
Ensure that the dialog is the same as the image above. Press OK to close the dialog. Press OK again to close the Analysis Sets. When asked by AutoPIPE, press Yes to run the analysis.
Press OK on the Analyze All dialog.
15 ISO 14692 FRP
8.2
ALLOWABLE CALCULATIONS
In order to determine the allowable values for each point and combination, AutoPIPE must perform the following calculations internally during the analysis.
8.2.1.1 PLAIN (RUN) PIPE Plain pipe shall be checked either using the fully measured envelope or the simplified envelope. Which envelope is used is dependent on whether the long term axial stress at a 1:1 stress ratio and long term hoop stress at a 1:1 stress ratio are defined, or not. If they are defined the fully-measured envelope is used. If they are not defined, i.e. equal to 0.0, then the simplified envelope shall be used. The fully-measured and simplified envelopes for plain (run) pipe are described in the following sections.
8.2.1.1.1 FULLY-MEASURED ENVELOPE The equations used for determining the fully-measured envelope are derived from equation 16:
16 ISO 14692 FRP
Using the following relationships: σqs = σhl(2:1) σhl(2:1) = 2*σal(2:1)
To get the following: σh,sum ≤ f 2*A1*A2*A3*σhl(2:1)
and, if σh,sum ≤ f 2*A1*A2*A3*σhl(1:1)
then use σa,sum≤ f 2*A1*A2*A3*σal(0:1) + [(σal(1:1) – σal(0:1))/σhl(1:1)]*σh,sum
else if σh,sum > f 2*A1*A2*A3*σhl(1:1)
then use σa,sum≤ f 2*A1*A2*A3*σal(1:1) + [(σal(2:1) – σal(1:1))/(σhl(2:1) – σhl(1:1))]*(σh,sum – f 2*A1*A2*A3*σhl(1:1))
8.2.1.1.2 SIMPLIFIED ENVELOPE The equations used for determining the simplified envelope are derived from equations 19 and 21 (2005 Corrigendum 1) of the ISO 14692 piping code:
Where, σqs = qualified stress σal(0:1) = long term axial stress at 0:1 stress ratio
Again using the following relationships: σqs = σhl(2:1) σhl(2:1) = 2*σal(2:1)
Where, σhl(2:1) = long term hoop stress at 2:1 stress ratio σal(2:1) = long term axial stress at 2:1 stress ratio
To get the following: σh,sum ≤ f 2*A1*A2*A3* σhl(2:1) σa,sum≤ f 2*A1*A2*A3*σal(0:1) + [(σal(2:1) – σal(0:1))/σhl(2:1)]*σh,sum
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8.2.1.2 JOINTS AND BENDS Joints and Bends are checked using the simplified envelope or the rectangular envelope. Which envelope is used is dependent on whether the biaxial stress ratio, r. If r is less than 1, then the simplified envelope shall be used. If r is greater than or equal to 1, then the rectangular envelope shall be used. The simplified and rectangular envelopes for Joints and Bends are described in the following sections.
8.2.1.2.1 SIMPLIFIED ENVELOPE The equations used for determining the simplified envelope are derived from equations 19 and 22 (2005 Corrigendum 1) of the ISO 14692 piping code:
Where, σqs = qualified stress
r = biaxial stress ratio To get the following: σh,sum ≤ f2*A1*A2*A3* σ hl(2:1) σa,sum≤ f2*A1*A2*A3*r*(σqs/2) + (1-r)*(σh,sum/2)
8.2.1.2.2 RECTANGULAR ENVELOPE The equations used for determining the rectangular envelope are derived from equations 19 and 23 (2005 Corrigendum 1) of the ISO 14692 piping code:
Where, σqs = qualified stress
r = biaxial stress ratio To get the following: σh,sum ≤ f2*A1*A2*A3*σ qs σa,sum≤ f2*A1*A2*A3*r*(σqs/2)
8.2.1.3 TEES Tee points use the rectangular envelope, where r = 1 for tees. 18 ISO 14692 FRP
8.2.1.3.1 RECTANGULAR ENVELOPE The equations used for determining the rectangular envelope are derived from equations 19 and 23 (2005 Corrigendum 1) of the ISO 14692 piping code:
Where, σqs = qualified stress
r = biaxial stress ratio = 1 (for tees) To get the following: σh,sum ≤ f2*A1*A2*A3*σ qs σa,sum ≤ f2*A1*A2*A3*(σ qs/2)
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9 9.1
POST PROCESSING DEFINING LOAD COMBINATIONS
Now that we have defined the load cases and run the analysis, we will look into the recommended load combinations. By default, AutoPIPE generates load combinations suggested by the ISO 14692 standard. To open the Combinations dialog, select Tools > Combinations and select the Code Comb. tab. The grid should look similar to the one below:
Note the f2 Factor column. This is the part factor for loading, used in the allowable stress calculations. •
Sustain – f2 = 0.67
•
Occasional – f2 = 0.89
•
Combined – f2 = 0.83
Note: The default values above can be modified in the Result Model Options dialog.
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9.2
SETTING MODEL RESULT OPTIONS
You can set the Result Model Options by invoking Tools > Model Options > Result . The Result Model Options will allow you to select different options like 'Use nominal thickness' , ‘Include torsion' etc. Enter the information on the Result Model Options as displayed below and press OK :
Note: Some of the options on the Result Model Options may not be applicable to ISO 14692 piping.
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10 RESULTS 10.1 GENERATE OUTPUT REPORT Finally, you can generate an output report by invoking Result > Output Report . Edit the options on the Batch Report dialog as displayed below and press OK to generate output report:
The output report will display the selected sections. Some sections from the generated output report are displayed below. Code Compliance Combinations:
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Code compliance:
23 ISO 14692 FRP
Code compliance report:
The code combination output contains the stress type, in- and out-SIF, bending stress, pressure stress, torsional stress, code stress and allowable stress. The stress ratio column compares the code stress to the allowable stress. Ideally, this stress ratio should be less than one (1). If the stress ratio is greater than one (1), the system will not satisfy the ISO FRP code requirements, which can be reviewed at the bottom of the result summary section of the output report. The mps value represents the pressure stress multiplier, and is 1.3 for mitered bends, 1.0 otherwise. In the rows for each combination, AutoPIPE reports the hoop effective and pressure stress, as mandated by ISO FRP. Maximum values are determined by dividing the hoop effective and axial stresses with the allowable values. Whichever solution has the greatest value will become the code stress. This is to determine the worst-case scenario, producing the greatest stress ratio. Therefore, the greatest bending and pressure stress may not necessarily be the considered code stress. Note: ISO FRP 14692 does not specify an allowable for thermal displacements.
24 ISO 14692 FRP
Result summary:
You can compare the archive for the model created through this walkthrough example (ISO_FRP_14692.DAT) and the output report generated for that model (ISO_FRP_14692.OUT) with the output for the model generated after running this tutorial.
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10.2 VIEW CODE STRESS COLOR PLOTS You can view color plots for the code stresses generated by the stress summary by invoking Result > Code Stresses . Enter the information on the Code Stresses dialog as displayed below and press OK to view the color plot for all HDPE code stresses as per the selected stress summary:
Clicking on a point will display the maximum stress or ratio at that point for the selected stress summary as displayed below:
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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.
27 ISO 14692 FRP
10.3 VIEW CODE STRESS ON THE RESULT GRID You can review the stresses in the model along with the color plot using the Result Review dialog. Invoke the Result Review dialog by invoking Result > Grids . Click on the Code Stresses tab and review the code stresses determined by ISO FRP 14692:
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.
28 ISO 14692 FRP
11 RESULT COMPARISON 11.1 COMPARING AUTOPIPE RESULTS WITH SUPPLIED OUTPUT FILE After reviewing the results, open the pre-existing OUT file and compare the results achieved by running through this tutorial with the expected results. If done properly, you should note that the results from the model generated by running this tutorial matches with the existing ISO_FRP_14692_FINAL.OUT file.
29 ISO 14692 FRP
QUIZ As a final step, a short quiz below will review some important features of the new ISO FRP 14692 standard. The following page will contain the answers to the questions below. 1.
What is the scope (purpose) of the ISO FRP 14692 standard?
2.
What type of design envelope AutoPIPE uses for Tee component allowable calculations?
3.
a.
Fully Measured
b.
Simplified
c.
Rectangular
The f2 factor is a partial factor used to determine the stress allowables. Where are these values modified in AutoPIPE?
4.
a.
Code Combinations dialog
b.
General Model Options dialog
c.
Result Model Options dialog
What is the default unit file used? a.
ENGLISH
b.
SI
c.
AUTOPIPE
30 ISO 14692 FRP
SOLUTIONS The solutions for the above quiz can be seen here. 1.
ISO FRP 14692 focuses on how to qualify and manufacture FRP (Fibre-reinforced polymer) and GRE (Glass Reinforced Epoxy) pipe and fittings, how to conduct system design and guidelines for fabrication, installation and operation.
2.
C
3.
C
4.
B
