Comments, Questions and Answers

1. Question:
   
   AutoPipe Results> Code stresses floating dialog shows the Max Expansion Stress to be 4785 psi on the screen however, the report shows 2 stresses (+ /- side) for that node point, one of which has a higher stress of 5004 psi ?
   
   Answer:
   
   The CAE development team has confirmed there is a problem on the floating results dialog for displaying the highest value stress between +/- side (up stream / Down stream) of a node point for bend mid point . The output report and results grids are correct.
   
   This has been loged under CAE-TR-11039.
   

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Problem:

What are some typical modeling approaches for subsea (underwater) piping?

Answer:

1. Concrete Mattress:

   Assuming the pipe is correctly supported by soil properties, select a range of piping where concrete mattress will be laid across, select Insert> Distributed load..> suggest "Load case to combine with " = GR, enter correct value of weight in vertical down direction, and press OK button to apply.

2. Concrete Encased Steel Pipe:

   There is no accurate way to simulate this analysis. In order to correctly account for the pipe & concrete stiffness, you would need outside program values for total pipe stiffness (pipe & coating), 
   
   OR, suggest to calculate an equivalent steel thickness by calculating the equivalent moment of inertia.
   
   Es*Ie = Es*Is + Ec*Ic
   
   Where Es, Ec stand for modulus of elasticity of steel and concrete respectively.
   
   Ie, Is and Ic are the equivalent moment of inertia, steel pipe inertia and concrete pipe coating inertia. The inertia can be approximated by
   
   Pi * R^3 * t
   
   R is the mean radius of the pipe or coating.
   
   Assume equivalent radius is same as steel radius and solve for equivalent thickness. You can recompute equivalent radius and solve again for new thickness.
   
   Please note you may use 1/2 or so (cannot recall exact number as neutral axis will move) of the concrete inertia as it will crack in tension. AutoPipe will give you stress in the equivalent steel pipe. You may need to evaluate the stress at most stress point by splitting the moment between pipe
   and coating proportional to their E*I.
   
   For example Ms = M * EsIs/EsIe and Mc = M* EcIc/EsIe
   
   And calculate stress for pipe and concrete using their actual diameter,thickness and material.
   
   So in conclusion, of modeling a concrete encased steel pipe, based on the information above:
   

   1. Insert a pipe property
   2. Combined Concrete / Steel Stiffness:
         a. Set Pipe material = Ns (nonstandard)
         b. Calculate / insert the pipe properties for the combined Concrete / Steel Pipe

   3. Account for weight and correct size:
         a. Set insulation thickness = XXX inches
         b. Set Insulation material = Other
         c. Set Insulation density = XXX lbs/cuft ( for concrete only).
         d. Set Density = XXX lbs/cuft ( for steel only)

   Note: setting the correct insulation thickness, insulation density, and pipe density will accurately account for the weight and outside dia of the combined pipe/ concrete for the wind / wave / current loading.

   4. Because the material is set to NS, update the data on the Press / Temp/ PipeID tab.

         a. Calculate and insert the expansion coeff, hot mod, and hot allowable based on the combined
              concrete / steel pipe.
   
   Notes:
   
   1. Take care not to double up on insulation/lining density and pipe density
   

3. Is AutoPIPE software suitable for the analysis of subsea pipeline crossings?
   
   AutoPIPE is limited to small displacement analysis and elastic pipe material. As long as these limitations are justified, you may use AutoPIPE for pipe stress analysis. Small displacement assumption implies that the pipe deflections will not severely affect computed forces and moments. For example if a simply supported horizontal beam of length L deflects L/4 at the mid span, this will be considered a large deflection since pipe weight is no longer supported by moment alone. Axial force or cable catenary action will contribute more to pipe resistance than moment in this case. AutoPIPE analysis for straight beam will show a zero axial force which is not correct if the vertical deflection is large.

   In some cases the user may require a strain limit instead of stress allowable limit, AutoPIPE results will be conservative since we do not allow yielding of pipe material. A material nonlinear model may be required to justify larger deflections in this case.

   Ultimately the client has to approve the use of AutoPIPE knowing the limitations ove the program.
   
   Bentely's CAE development team is constantly updating the application with new enhancements and abilities. Please review the latest version of AutoPIPE for current capabilities and limitations.

4. Does AutoPIPE consider external pressure or temperature.
   
   AutoPIPE does not consider external pressure or temperature. However, the external pressure can be approximately accounted for by subtracting it from internal pressure.  External temperature can be approximated finding the average pipe temperature using heat transfer concepts. Other wise use bounding values, like higher and lower temperatures as two separate load-cases.
   
   See AtuoPIPE FAQ#36: How do I calculate the DNV 2000 tension terms.
   
   
5. Can you then confirm that AutoPIPE is not suitable for deep offshore analysis as regard to calculating true pipe wall force which will take into consideration the end cap effect and external pressure?
   
   AutoPIPE does apply the axial force created by hydrostatic forces. This is included in the buoyancy for the GR load case. 
   
   External pressure can be approximately accounted for by subtracting it from internal design pressure.
   
   AutoPIPE has been successfully deployed on many deep water riser analyses. Usually the pipe is close to vertical or lies on the sea bed. Stinger pipes cannot be analyzed in AutoPIPE as we do not handle catenary action.
   
   
6. Is it possible to simulate the free catenary for subsea pipeline?
   
   Our software AutoPIPE does not support large displacement and tension stiffening and hence should not be used for free catenary systems. It has been successfully for riser piping which is close to vertical for which such action is insignificant.

7. We are modelling offshore pipeline and Riser at 50' water depth in sandy soil. Pipeline is buried 2' below sea bed and close to platform it is exposed. Which method we shall adopt for calculating soil spring? AUTOPIPE Method or ASCE 2001 Method. our client wants to know which one is realistic and why?
   
   Answer: Due to liability lawsuits Bentley Technical support cannot provide specific or settings for your analysis. Please see the following AutoPIPE help section:
   Help > Contents> Contents Tab> Reference Information> PipeSOIL overview> Comparison of Soil Restraint Properties for detialed difference between these soil calculations. The user must determin which soil method is appropriate for their analysis.

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

The following Static Analsyis enhancements have been logged for inclusion into a future version of AutoPIPE:

1. CAE-CR-9970 Allow user to specify OCC case as an initial state for another OCC case
   
   Description: On the load sequencing dialog screen, allow user to specify an Occasional load case (i.e. Wind, Earth, or User) as an initial state for another Occasional case.
   
   Development Project:  .TBD
   

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Problem:

Follow errror message inside of Tools> Model Consistency Check report:

E726-104: Zero length not allowed at beam M5

How to resolve?

Answer:

 Open AutopIPE and the beam tab on the input grids, locate the beam and open the dialog screen:

Notice that the connect to point J has a node point name, however all DX, DY, and DZ values are zero.

Avoidance: choose one of the following:

A. Enter a value greater than 0.00 in one or more of the following fields: DX, DY, and /or DZ.

B. Delete the beam completely.

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

The "Code Compliance" grid displays the combination set defined for piping code compliance (both the default combinations and user-defined sets). Any default code combination may be modified, deleted or reset and any new user combination created and modified in the same grid.

User Code Combinations dialog

Questions & Answers:

1. I wish to define the allowable hoop and longitudinal stresses for a user code combination that i have set up.
   
   Answer: Per the online help:
   
   The Allowable Stress field on the "Code Comb." tab of the Load Combinations dialog enables the user to define the allowable stress for any Code Compliance combination directly. Select Tools> Combinations > Code Comb. TAB, uncheck  and modify the values in the Allowable Stress column.
   
   Notes: This field is only enabled when the "Auto Update" check box option is disabled (checked OFF).
   
   
2.  What is the M/S column for?
   

   Answer:

   To illustrate the use of M/S level in combining stresses we will look at combining the sustained stresses with the wind stresses.

   1. Absolute sum of the stresses from SUS and stresses from W1. This is the logical and conservative way to calculate the combined stresses but the user could not select M/S=S for W1. Default method in AutoPIPE since the ASME codes state sum the sustained stress with the bending stress due to Wind (occasional load).

      NOTE: SUS is the maximum sustained stress and equals GR+MaxP when only one sustained stress combination.

   2. Absolute sum of the moments & forces from SUS and moments & forces from W1. Based on AutoPIPE's recommendation that M/S=S for SUS, this is not the method AutoPIPE would combine the stresses.

   For Sus.+W1, AutoPIPE is combining stresses according to method (a.) above. The M/S option refers to calculated results - Moment (M) and stress (S) - prior to combining. There are three types of results:

   1. Basic load cases, e.g. GR, T1, W1 etc have only moment results and hence (S) does not apply.
   2. Category stresses, e.g. Sus., have both calculated stress and moment results.
   3. Combinations, e.g. Sus.+W1, have both calculated stress and moment results.

   The moment results for W1 are used to calculate the stress before combining with the stress results from the sustained category stress (Sus.).

   Example

   Here is another example to illustrate the subtle results using the M/S options.

   Example: Sus.+W1+T1

   Approach 1

   Create a combination with (SUS), W1, and T1 using combination method SUM with the following M/S options,

   (SUS): M/S = S
   W1: M/S = M
   T1: M/S = M

   Approach 2

   First create the combination with (SUS) and W1 using combination method SUM with the following M/S options,

   (SUS): M/S = S
   W1: M/S = M

   Then create a second combination that combines the above combination Sus.+W1 with load case T1 using combination method SUM with the following M/S options,

   Sus.+W1: M/S = S
   T1: M/S = M

   The combined results using Approach 2 is more conservative than using Approach 1 since the stress results are always positive before combining in Approach 2 whereas the algebraic signs in W1 and T1 are considered in Approach 1 when combining moment results before calculating the combined stress.

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Topics under the heading should be based on:

Library data

1. Can I migrating customize library files to newer versions of AutoPIPE?
   
   
   Answer: The CAE development team is always manipulating the program to add new enhancements or fix known issues. As a result there is no way of knowing if any of the lirbrary files content / format has been changed / updated from the previous version(s). 
   
   Therefore as a rule of thumb, never use a library file from one version of AutoPIPE to another. Recommend getting the new library source file and coping the customized information into it. This procedure will ensure that your model is correct for the version of AutoPIPE being used.
   
   
2. Add New Material to Existing Library, AutoPIPE 6.0

3. Add New Material to Existing Library, AutoPIPE V8i v.9.0 and higher

Problem:

In addtion to the "StressISO_Troubleshooting.pdf" document found on your hard drive, see the following information: 

TR Number: None
Product: AutoPIPE
Version: n/a
Area: General
Problem ID#: 72015

Answer:

solution 500000088706

Information:Isogen is a 3rd party software that is bundles with many cad applications such as Bentley AutoPIPE to automatically produce an isometric drawing. Isogen is very particular about the format of the data being converted into an DXF, DWG, or DGN file format. If there is one error in the data Isogen may hang, display a message about warnings with the file, etc...

Use the following steps to trouble shoot an Isogen related issue with AutoPIPE:

1. Known issues

Known issues are documented in the StressISO_Troubleshooting.pdf located in the AutoPIPE folder. Review this document to see if it is a known issue.

2. Isometric based on actual pipe components:

For an example, AutoPIPE can model a tee where the branch axis matches the same direction as the tee's header pipe axis. This is wrong modeling but can be done in AutoPIPE.

However, Isogen will abort because it knows that a tee like that cannot be constructed. In order to export the model, the tee must be fixed so the branch axis does not match the header axis.

The goes for all other pipe components, if the actual component cannot be drawn because of dimensional issues or arrangement, then isogen will abort trying to create a stress iso.

Recommend:

a. Review all valves and flanges closely. Be sure all are modeled correctly
b. Review Tools> Model Consistency Check report to reduce number of warnings.
c. In general, review model looking for obscurities.

Typical issues:
---------------------

a. Flanged valve in middle of pipe run without attached flanges, add flanges to both sides of valve.

b. In middle of pipe run, back to back flange set. Upon closer inspection, there are 3 flanges. Remove the correct flange.

c. Known limitation, reducer cannot be the start or end of segment. Add short pipe run from reducer.

d. Middle of pipe run where 2, 4 inch dia, branches are placed side by side on top of the pipe. However branch center lines are only 3 inches apart causing an overlap. This can be modeled but not exported to Isogen. Fix by reducing branch size or moving center lines apart.

e. Kink in pipe of 179.9 deg, remove pipe kink.

f. W726-170:The tee at point E00 has only two legs, fix by adding a branch run pipe, or change Tee node to a Point node.

3. Where is the warning occurring

If the following is displayed:

---------------------------
ExecISO
---------------------------
There were some warnings and/or errors while executing ISOGEN.
Do you want to review messages:
---------------------------
Yes No
---------------------------

Select the Yes button and

C: \Bentley \AutoPIPE V8i SELECTseries \PISOGEN \PROJECTS \APIPEPROJ \FINAL \OUTPUTFINAL.MES

is automatically displayed. Review the entire document and try to resolve any and all warnings displayed.

4. Disconnected systems:

Before creating a stress iso, review the model segments to be sure they are connected and do not stop at a component (i.e. valve, reducer, bend). Sometimes a run of pipe is broken into multiple segments on the same run of pipe. Remove any additional segments by jointing them at node points.

In addition, with a complicated model use the following feature: Select> Connected segments> choose only one box to highlight a connected series of pipe. AutoPIPE stress iso cannot process 2 disconnected segments at the same time.

With one group of piping selected, create a stress iso as before, and be sure to confirm the "use connected segment" check box is checked ON.

Note: If using "Modeling a "dummy leg" as a structural member or a pipe" modeling technique, stress Iso cannot generate the dummy support. Only 2 workaround suggestions: a. use a different modeling technique allowed by ISOgen or b. manually modify isometric after being created in a cad application.

5. Clean folder

Create a new folder on the Desktop, copy the model's DAT file to the new folder, start AutoPIPE, open the file from the new folder location, run the analysis, try to create a Stress iso DXF file instead of DWG or DGN file.

6. Model Size Limitation:

Isogen has some model size limitations. Try selecting a portion of the model that is completely connected and creating a stress iso based on the select set. See #5 above for technique to select connected segments. Otherwise, need to manually create a selection set of connected segments.

7. Stress iso Template files

AutoPIPE V8i 9.3 and lower:

All Stress iso template files need to be saved into AutoCAD 2000 format only; see the following procedure:

1. Open the isogen title bock in AutoCAD

2. Once open, run an audit by typing A-U-D-I-T in the command line.
AUDIT command evaluates the integrity of a drawing and corrects some errors.

3. When completed, purge the drawing by typing P-U-R-G-E in the command line. The PURGE command removes unused items, such as block definitions and layers, from the drawing.

After the above has been completed, copy the file to the AutoPIPE folder

….C:\Bentley\AutoPIPE V8i SELECTseries3\PISOGEN\BORDERS

In order to use the new border file, under "Isogen Settings" confirm: Drawing Frame File, User Defined, Plot Frame, Drawing Size, AutoCAD units, Dimension/Tex formats settings.

See following link as help

http://communities.bentley.com/other/old_site_member_blogs/bentley_employees/b/joeys_blog/archive/2010/06/03/ddt-audit-generated-on-autoplant-piping-isogen-drawings.aspx

AutoPIPE V8i 9.4 and higher:

Skip the last step for saving to previous version and only A-U-D-I-T, P-U-R-G-E is required before saving the file to 2010 - 2012 format.

8. Switches:

There are 100's of switches that can be adjusted for isogen. Recommend resetting these switches by overwriting the Stressiso.ini and Apipe.opl files with a default copy of each file. Or, use a copy from a person's computer who does not have such issues when creating an iso from the same file that you are having troubles with.

Reset Default Settings
-----------------------------------------------------------------------------
Stress iso stores dialog settings and other information in a variety of files/locations:
___a. Stressiso.ini
___b. Apipe.opl
___c. C:\Bentley \AutoPIPE V8i SELECTseries \PISOGEN \PROJECTS \APIPEPROJ \Final

Depending on configuration, settings enter, or anomalies there could be a conflict when creating a stress iso. Only after completing all the above steps 1-8 should this resolution be considered. The best solution is to reload the default settings again before trying to run stress iso. The easiest method of resetting the default values is over write the current files with a copy of the original files when the application was installed. If you do not have a copy of the original files, suggest uninstall/reinstall the application.

9. Register DLL

The following is displayed in the Final.MES:

***** POD Error(s) *****
Unable to initialise POD : Failed to generate POD - Conversion failure :

Register all DLL
---------------------------------------

a. Close AutoPIPE

b. Log into computer with Admin Rights

c. Locate Register.dll, generally found in "C:\Program Files (x86)\Common Files\Bentley Shared\Plant V8i\Isogen".

d. Right click on the file, select "Run as Administrator" option

e. The screen will display the Dos cmd window and automatically register the following DLL's in the system:
____pipeline.dll
____skey.dll
____importexport.dll
____pod.dll
____pisogen.dll
____materialdata.dll
____smartrad.dll
____catmanager.dll
____idfgen.dll

Note: these DLL should have been registered when the application was installed. Something had prevented them from being registered correctly.

f. Restart AutoPIPE and try to create a new stress Iso drawing.

Register specific DLL
---------------------------------------

a. Close AutoPIPE

b. Locate POD.dll, generally found in "C:\Program Files (x86)\Common Files\Bentley Shared\Plant V8i\Isogen".

c. Open the command-line prompt
____Start Menu> Run
____Type "cmd"
____Press "ENTER" or "Return" keyboard key

d. Using the POD.dll filename and path, call regsvr32, i.e. at the command-line prompt, type:
____ regsvr32 "C:\Program Files (x86)\Common Files\Bentley Shared\Plant V8i\Isogen\pod.dll"
____ Press "ENTER" or "Return" keyboard key

e. You should see a regsvr32 window, confirming success: Close it.
____RegSvr32
____DllRegisterServer in C:\Program Files (x86)\Common Files\Bentley Shared\Plant V8i\Isogen\POD.dll succeeded.

Press "OK" button.

f. Restart AutoPIPE and try to create a new stress Iso drawing.

10. Dimensioning Stress Iso

On the "Stress Isometric Options" dialog, click on the "Isogen Settings" command button, or select Tools > Settings > Isogen…> select the "Dimension / Text tab" displays the current options/settings for adding dimensions and text on a stress Iso drawing.
The Stress Iso utility has a limited number of options available for dimensioning a model and are all listed in the dialog. Any options or type of dimensioning not listed would be considered an enhancement. Please log a service ticket requesting the enhancement in detail.

11. Dimensioning across segments and flanges appear incorrect

A stress Iso was created for a given model. On the stress Iso, it has been observed that the total length of pipe from the pipe end to a flange set (Dim A) and distance from flange set to bend TIP point (Dim B) adds up to be correct total distance. However Dim A and Dim B do not equal the actual values in the model. Additional note, the flange set is at the junction point between 2 connected segments.

As AutoPIPE does not have the length for the flange and it cut the pipe to arrange the space for the flange. As for normal pipeline this scenario works perfect but there is a limitation in AutoPIPE that if the flanges placed on the segment continuation point then the space allocation for flanges can be cut from the one side. By that there was the change in the length which is equal to the flange hub length (ex. 305mm).

The avoidance is to join the segments by selecting the node point between the segments (ex A04) and go to "Edit > Segment > Join" and then export to stress ISO. Then Dim A and B on the model match that in the exported stress Iso drawing. The CAE development team will be adding a 2 point flange in AutoPIPE V8i 9.7project to dismiss such scenarios as seen above.

12. Nothing happens after pressing OK on Isogen settings dialog
(iso not created)

Application was not installed using full administrative rights. Uninstall and re-install AutoPIPE with full admin rights

13. Drawing file is not created, but PCF file is:

___A. Be sure that AutoPIPE was installed on the computer with a person who has has full admin rights. If unknown, completely uninstall the program, delete AutoPIPE folder, reboot the computer logging in with admin rights, reinstall the application.

___B. Check to see if the version of AutoPIPE installed is listed in "add/remove programs" (Win XP) or "Program and Features" (Win 7). If not listed, completely uninstall the program and reinstall with full admin rights.

___C. If the above does not resolve issue send computer information by performing the following:
Computer's system information:
1) Start> Programs> Accessories> System Tools> System Information.
2) After the program has been opened, select File> Save> save file
3) Send me a copy of systemname.NFO file for review.

___D. Also, perform the following:
1) Start DOS command, select Start> Run> type "cmd"
2) Type, cd .. until c:\> is shown
3) Type, c:\> Dir /s /o /ogne>systemname.txt
4) Send me a copy of the systemname.txt for review.

These files may be large and can be shrunk by adding it to a ZIP file. Create a service ticket and send files for review

14. Anchor symbol is not drawn correctly:

Please follow these steps.
1. Close AutoPIPE
2. Open AutoPIPE's installation folder, C:\Bentley\AutoPIPE V8i SELECTseries\
3. Locate the following file "PCFout.map"
4. Open this file in any text editor (i.e. notepad)
5. Go down to line 41, see the following:

ANC SUPPORT 01AN

6. Change "01AN" to "ANCH", should look like:

ANC SUPPORT ANCH

7. Save the file.
8. Open AutoPIPE, run an analysis, process a new stress iso.
The problem should be solved.

15. Drawing file not created after stressiso dialog closes for a very large model:

When I try to create a stress Iso the PCF file is created in the folder, however the drawing file is never created. In addition the program issues the noticed that the drawing has been completed.

Answer: The following was shown in the following file:

C:\ Bentley\ AutoPIPE V8i SELECTseries\ PISOGEN\ PROJECTS\ APIPEPROJ\ FINAL\ OUTPUT\ FINAL.MES

START OF DRAWINGERROR DETECTED IN PIPE /drawingname
********************************************************************************
ERROR:
Message Identifier: ISOGEN:1007
Message Text: OVERFLOW IN PIPELINE DATA
PIPELINE REJECTE

Avoidance: divide the larger model into smaller models using the window selection of AutoPIPE.
First export the first selection and then export each additional selection.

16. Cannot be resolved:

If the problem still persists and cannot be resolved by the above suggestions complete the following:
=================================
a. Create a new folder on the Desktop
b. Copy the model's DAT file to the new folder
c. Start AutoPIPE & open the file from the new folder location
d. Run the analysis
e. Create a Stress iso DXF file
f. If the warning in #2 above appears, select OK button
g. Close AutoPIPE
h. Zip all the files in the new folder on the desk top
i. Zip all the files in the following location:

"C:\Bentley \AutoPIPE V8i SELECTseries \PISOGEN \PROJECTS \APIPEPROJ \FINAL"

j. Include the following files from the AutoPIPE application folder. "C:\Bentley \AutoPIPE V8i SELECTseries\:

_____ - i. Stressiso.ini
_____ - ii. Apipe.opl

k. Create a service ticket at:http://appsnet.bentley.com/srmanager/addcall.aspx

Attach both Zip files to the service ticket and submit for review.

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Topics under the heading should be based on:

Component modeling with associated dialogs

1. **Attention** Please see the following AutoPIPE help section:
   Help > Tutorial>
   
   This help has been provided in order to give users ideas for modeling typical piping arrangements. The steps shown in each example should not be taken as the only method available to create models. In addition, the intent of the examples is to present ways to create adequate models for analytical purposes. 
   
   Tutorial #1 : Acoustic Mode Shapes
   
   The purpose of this tutorial is to introduce the basic operations of the PULS application.  The tutorial will
   show you how to produce acoustic mode shapes of a simple system. It will walk you through the various
   steps in model building. You will define the piping system by specifying system geometry, fluid
   properties and boundary conditions. You will learn how to view and print your results.
   
   
   Tutorial #2 : Modeling a Reciprocating Compressor
   
   The purpose of this tutorial is to introduce the basic operations of PULS to model a reciprocating
   compressor system. This tutorial assumes that you have not completed Tutorial 1, therefore, some of the
   information may be repeated.
   
   
2. The following model files are included with PULS :
   
   2CYL.LP1 - TWO CYLINDER COMPRESSOR EXAMPLE  
   COOLER.LP1 - GAS COOLER
   EX-BOT.LP1 - SUCTION BOTTLES AND COMPRESSOR
   EX-SUCT.LP1 - SUCTION SYSTEM
   METER.LP1 - METER RUN : Globe Valve Source
   PISTON.LP1 - Piston (Volume Velocity) source.VS = 0.01 m3/sec, Natural gas/ sound speed = 494 m/sec
   PRESURE.LP1 - Press source for a branch system., PS = 10 kPa, Natural gas, sound speed = 494 m/sec
   PUMPFIX.LP1 - PULS models involving a reciprocating triplex pump
   PUMPSUC.LP1 - PULS models involving a reciprocating triplex pump
   RECIPP. LP1 - RECIPROCATING COMPRESSOR EXAMPLE
   T1. LP1 - Pulsation Source: T1 - Mode 1
   T1-1. LP1 - Pulsation Source: T1 - Mode 1
   
   
3. We would like to know if PULS (Option 3) is suitable for modelling the shaking forces in dead-leg side branches from vortices generated by a corrugated pipe with flow. We already know the amount of energy and flow conditions which the vortices generate in the corrugated pipe, so PULS does not need to calculate them. We just need a way of putting in an energy source in the (e.g. middle of the corrugated pipe). We have considered using a suitably scaled velocity source or pressure source, but both of these  would impose reflective boundary conditions (like an open or closed end) which do not exist in reality. Is there a way of modelling this in PULS?
   
   Answer: Suggest to try and  insert a tee point on the tee branch very close to tee point. The length would be short and you would add a velocity source there. They can scale the source to give a known pulsation at the dead end if known.
   

4.  

    

   
   
   
   

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Topics under the heading should be based on:

Calculations in PULS

1. **Attention** Please see the following AutoPIPE help section:

   Help > Contents> Reference>

   This page provides references used in the creation of the program.

2.  How to calculate liquid pump according to help file of puls. could you provide some instruction on how to make liquid pump model  and check it? could puls support liquid's model building and checking?

   Answer:  PULS does not have a centrifugal pump. If they have to model it I would use a pipe or reducer or something to simulate volume or length.  Noise cannot be simulated from centrifugal pump. If you have to, you may try a velocity source at a dead end near the pump. You may create a fictitious short branch and add a velocity source at the dead end.   For reciprocating pump you can choose the recip boundary condition and works the same way as recip compressor. We have two pump examples pumpsuc and pumpfix and they are documented in the comparison to experiment and on chapter on liquid modeling in the PDF manual.

3.  

Topics under the heading should be based on:

Bentley PULS Op1, Op2, or Op3

1. Installation

2. Error Messges

3. Modeling In PULS

4. Calculations in PULS

5.  

The Load> Static Analysis Sets command allows the user to define multiple static analyses (analysis sets) and provide references to these results from separate analyses during post-processing. Analyze > Static or  will analyze all selected static analysis sets.

The Static  option in the Analyze menu enables the user to perform all the selected static analysis sets considering any scenarios of gravity and thermal expansion loads, plus wind loads and/or static earthquake loads if they have been defined.

From inside AutoPIPE with a model opened, select Load> Static Analysis sets... after the screen appears press the "HELP" button for details on all the key features available on the dialog.

To define loadcases to be added to a specific analysis set, highlight a row by left clicking the mouse on the first square in the row, the row should be highlighted black with white lettering, now left click the "Modify" button. In a moment the"Static Analysis Load Cases" dialog should appear. AutoPIPE only activates load case input fields for currently defined load cases. Again press the "HELP" button for details of features available on this dialog screen.

"Static Analysis Sets" and
"Static Analysis Load Cases"  dialog
Questions and Answers  

1. My results does not appear to be considering weight of conents in piping for the analysis?
   
   Answer:
   On the "Static Analysis Load Cases" dialog screen is a check box for "Contents", confirm this box is enabled (checked ON) for all analysis sets as desired. Enable this option to include the weight of the pipe contents in the analysis of the gravity (GR) load case. This will cause the program to consider the respective pipe properties settings for all the piping in the model. The calculation for weight of pipe contents is based on the individual pipe ID's:
   
         A.  Inside diameter of a pipe
         B.  Specific Gravity of Contents (based on water).
         C.  Linear center line distance of a piping for a Pipe ID
   
   Each one of the 4 settings must be configured to correctly consider weight of contents in a piping systems for each Pipe ID and Analysis Set.
   
   Additional information is available to be reviewed in the Tools> Model Listing > Center of Gravity sub report. This option generates a section that reports weight and center of gravity coordinates for all the components in the model. The components are categorized as Valves, Flanges, Flexible Joints, Additional Weights, Pipes (includes straight runs, bends, tees and reducers), and Beams. Weight and center of gravity coordinates for Insulation, Insulation Cladding, Lining, and Contents are also reported as separate categories. Weight and center of gravity coordinates of different combinations of the categories are also reported (see online help for details on this report).

2. 
    

3.  

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

 AutoPIPE is able to import a variety of file formats. However, CAESAR and Aveva PDMS read/write ability is very restrictive and can only communicate with AutoPIPE through the CII file format. Therefore the ability to read/write information between the 2 applications is well documented in AutoPIPE's online help, including complete information on mapping components.

Attention: Please see the following AutoPIPE help section:
Help > Contents> Search Tab> enter "Caesar CII Mapping" (include the quotes), press List Topics button, double click on the selected topic from the list provided to see more information about:

• Node Number Mapping

• Component Mapping

• Support Mapping

• Load Case Mapping

• Limitations

Frequently Asked Questions

1. Typical problems with importing CII files into AutoPIPE files

2. Imported CII file with segment origin points are reset to 0,0,0.

3. After importing a CESAR file into AutoPIPE, found that after pressing the toolbar button "Show Pipe Properties" does not have an option to view "ALL" Pipe identifiers. Did the import corrupt the program?:

4. The translation of Cii support to AutoPIPE produces arrangements that look messy (using a mixture of Inclines and other supports).

5. Imported CEASER file appears to open, but does not, and program crashes displaying " Bentley AutoPIPE Application is not responding"

6. Load Cases not defined when importing Caesar cii file.--I'm trying to import a .cii Caesar file, and the load cases are not defined. The geometry is there but I can't place any load cases.
   
   Answer: Once the cii file has been opened you must reset the load cases to run the analysis. Instead of selecting the icon to run a static analysis, go to the dropdown menus and select Load> Static Analsysi sets, confirgure the analysis set, press OK button, choose Analyze> Static, and then review combinations with Tools> Combinations command.
   

Error message on Caesar Import:

1. Caesar imported file caused "forrtrl: severe (64) - Input conversion" error

2. The following is displayed:
   
   TEE 3710 F 0.0000 0.0000
   *** ERROR: CANNOT PUT TEE AT THIS POINT. TEE IGNORED.
   
   

   Answer:
   This is caused when a tee is configured for a location that AutoPIPE cannot phiysically place a TEE because of an internal component connection based on the CII configuration.

   Solution:
   a. Open the CII file in any word processing program.
   b. Search for the location indicated in the error message
   c. See attached file for CII file format details
   d. In the element section, move up a few elements and hand sketch the elements down and past the indicated point.
   e. Review the other section to verify correct settings (i.e. is the tee at the intersection point, is the bend radius correct, pipe diameter, etc..

   In this scenario, the SIF & TEES section had a intersection point that had the wrong name. Modify the tee intersection point with the correct name an file is able to be imported without any errors.
    

3.  

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Problem:

AutoPIPE: install multiple ver. same computer

Can we install mutliple version of AutoPIPE on the same computer?

TR Number: none
Product:
AutoPIPE
Version: n/a
Area: General, installation
Problem ID#: 80537

Answer:

 Quick answer: Yes, BUT....

You can install multiple versions of AutoPIPE on the same computer using the following instructions:

Options:
==========================================================
1.  Create multiple instances of a Virtual Machine (VM) on the same systems and install a different version of AutoPIPE in each VM

or

2. Install the different versions of AutoPIPE in ORDER!!!
Example: want to install AutoPIPE 8.5, 9.2, 9.4 on the same system.

____a. Install oldest one first, completely install AutoPIPE v8.5

____b. The application will be installed to the default folder location: "C:\Program Files\Bentley\AutoPIPE\",

____c. Open the folder location and rename the folder to something other than the default name (ex. AutoPIPE_08.05.00.12). This is an important step because, when the next version is installed, it will be installed to the default location and does not overwrite the already installed software. Renaming the folder location will break the shortcut designations on all the desktop and menu icons. Manually update these shortcuts as required. Also, recommend naming the menu group/icon names to be descriptive of version applicable to.

____d. Install the next release (v9.2) progressing in order with the next highest version number using all default settings.

____e. The default location for all V8i versions is, “C:\Bentley\AutoPIPE V8i SELECTseries”, again rename the default folder name to another name (ex. AutoPIPE_09.02.03.02), fix all short cuts in the menus and desktop.

____f. Install the newest version last (ex. 09.04), using the default settings.

____g. After All AutoPIPE versions have been installed, install the latest version of Bentley IEG.

____h. If AutoPIPE 8.6 and lower was installed, need to install Bentley Gateway and Plant security as documented
in the installation files.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

IMPORTANT:
Do not install an older version than the last one installed on the system as it will corrupt files in other system folders, i.e. Isogen. Example, after installing AutoPIPE V8i 09.04.01.05 do not install, AutoPIPE 2004 08.06.00.12. Only workaround, uninstall all AutoPIPE versions and reinstall in chronological order.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Topics under the heading should be based on:

Release notes, Hardware related issues, Download, Installer issues. Missing components, short cuts, user access rights etc.

1. Bentley AutoPIPE Release Notes

2. Hardware Related Issues

3. Performing a silent installation

4. Installing AutoPIPE on an untested Operating System, (i.e. Win 8)

5. Install multiple versions of AutoPIPE on the same computer

Any Comments, Questions and Answers about exporting an AutoPIPE Batch NTL file from AutoPIPE

Comments, Questions, and Answers:

 1. When AutoPIPE exports an AutoPIPE Batch (NTL) file the following is displayed:


Bentley AutoPIPE ApplicationBentley AutoPIPE Application has stopped workingWindows is checking for a solution to the problem...

then the following is displayed:

Bentley AutoPIPE ApplicationBentley AutoPIPE Application has stopped workingA problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available.[Close program] button

Reasons this occured: 

1. The model contains invalid value(zero) for pointer to buried pipe options

Solution #1

A. Change piping code from B31.3 to B31.1 because buried pipe option is not available in B31.3

B. Open Buried Pipe Options dialog (Tools> Model Options > Buried Pipe Result Options) and Press Ok so that buried pipe options pointer will be updated

Solution #2

A. Change piping code from B31.3 to B31.1 because buried pipe option is not available in B31.3

B. Open Buried Pipe Options dialog (Tools> Model Options > Buried Pipe Result Options) and Press Ok so that buried pipe options pointer will be updated

2. The analysis set has a fluid density factor  that is blank.

Solution #1

A. Open the analysis set, Load> Analysis set.

B. Confirm that all Fluid Density Factors are not blank but have a valid value.

2. AutoPIPE: save model as *.NTL & open NTL

What are the concerns with saving an AutoPIPE model as an AutoPIPE Batch (*.NTL) file and then opening that
*.NTL file in AutoPIPE?

TR Number: none
Product: AutoPIPE
Version: all
Area: General
Problem ID#: 79405

Answer:

The process of saving an AutoPIPE model (*.DAT) file to an AutoPIPE Batch (*.NTL) file, and then opening the *.NTL file in AutoPIPE to create a new *.DAT file is referred to by us as "round tripping a model"

Information is saved to the AutoPIPE model *.DAT file in a database format with very specific settings and arrangement of data. The AutoPIPE BATCH file (*.NTL) is data written out from the database into a specific formatted text file. When the NTL file is opened in AutoPIPE, the model is created based on the NTL file settings. Because of translating data from DAT to NTL back to DAT, some data is updated with current library information, not exported from the DAT to the NTL file correctly, or other unknown issues. This is why it is VERY VERY IMPORTANT to follow this procedure:

1. Open original AutoPIPE model DAT file (Test.DAT)

2. Run an analysis.

3. Select Results> Output report> ensure all sub reports are checked ON,(except “Sort Stresses” should be turned OFF), save Test.OUT.

4. Select File> Save As > AutoPIPE Batch (TEST-1.BAT)

5. Select File> Open> AutoPIPE batch (*.NTL)> select file (ex.Test-1.BAT)

6. READ and understand any reports that is automatically displayed (ex. CHK, MSG, etc..)

7. Select Results> Output report> ensure all sub reports are checked ON,(except “Sort Stresses” should be turned OFF), save Test-1.OUT.

8. Use an application (i.e. Ultra Compare, Beyond Compare (free on internet)) to compare both Test.OUT and Test-1.OUT to CLEARLY see the differences.

9. IN MOST CASES, the new DAT file will need to be updated to match the original DAT file.

Again, it is very important to perform this process of file comparison and to thoroughly review the new DAT file to be sure of model settings.

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Each AutoPIPE translator is installed with a complete manual about the application. See the following file for more details about the translator program:

C:\Bentley\AutoPIPE Translators\PCF Translator \ SmartPlantToAutoPIPETranslator_UserReference.pdf

Issue #1:

PCF conversion worked, but when Import the converted NTL file into AutoPIPE the process aborted: what should I do?

Answer:

See the following link:

http://communities.bentley.com/products/pipe_stress_analysis/w/pipe_stress_analysis__wiki/7642.aspx

Issue #2:

All the AutoPIPE models that we import from Autodesk Inventor PCF files show flanges and valves as weightless “Zero Weight” components. Is there anything that we can do different on our end to have inventor PCF files carry-out the flanges and the valves weights?

Answer: Most common cause is your mapping (pcfin.map). Please see the following folder:

C:\Bentley\AutoPIPE Translators\PCF Translator\

Suggest that you review the all files in this location for complete details on this feature. To answer your question directly, your PCF file is not mapping items correctly. Example of a model that imports a flange without error or warnings:

    ITEM-DESCRIPTION    Flange, CL150, RFFE/SWE, ASTM A182-F304, ANSI-B16.5, S-40S

Recommend adjusting PCF file with a valid description, or fix the map file to import your flanges to anything but the default settings.

If there is no mapping between skey item and type, then default will be applied, default is NS (nonstandard).

Issue #3

Q. When trying to convert a file from PCF to NTL, the converter freezes at “Parsing complete…” it never creates the NTL file.

Answer: Review the PCF file, duplicates of certain components on the same coordinates will cause the connecting logic in translator to hang. Therefor the current PCF file does not  seem like a valid / good PCF file. Open the original model to review duplicate components before exporting a new PCF file to be converted with the AutoPIPE translator.

Issue #4

Q. Program does not import a PCF file and hangs with no error message.

Answer: Review the original model for a closed loop. AutoPIPE does not support a closed loop (segment connected back to itself) and if detected will hang with no error message.

Another common  problem is that the "Description" is too long. Should only be max 60 characters

Example:

 DESCRIPTION    SUPPORT: Rigid Rod with Double Bolt Clamp, Top Type: WELDED BEAM ATTACH, Rod: Cont. Thread, 3/8 $  *PART:Anvil FIG295 1 1/2 in Double Bolt Pipe Clamp, Finish: Black $  *PART:Anvil FIG290 3/8 in Weldless Eye Nut, Finish: Black $  *PART:Anvil FIG146 3/8 in Continuous Threaded Rod, Length: 77.75 in, Finish: Black $  *PART:Anvil 3/8 in Standard Hex Nut $  *PART:Anvil FIG66 3/8 in Welded Beam Attachment (Connect to Bolt), Finish: Black $  *PART:Anvil FIG290 3/8 in Weldless Eye Nut, Finish: Black $

Avoidance: reduce description to smaller size, i.e.:

DESCRIPTION    SUPPORT: Rigid Rod with Double Bolt Clamp,

Issue #5

Q. When trying to convert a file from PCF to NTL, the converter freezes / aborts and it never creates the NTL file, why?

Answer: After reviewing the file, noticed that there are overlapping components which also freezes the PCF translator. The CAE development team will add some programming logic in the next PCF translator build to display a warning message. PCF translator v.1.0.0.29.

Issue #6

Q. Following is displayed when trying to open converted PCF , NTL file in AutoPIPE:

"E880-1: Error in opening import batch file. File extension must be NTL".

Answer: There is a known issue if the file name has a blank space before the file extension, the above message is displayed. Confirm that the file name does not have a blank space before the file extension, example: "Test .NTL", remove space "Test.NTL"

Issue #7

Below are general questions and answers about the process  of exporting an existing AutoPIPE model (DAT) to a PCF file, translate the newly created PCF file with the PCF translator back into an AutoPIPE model, and compare AutoPIPE results between before and after translation:

Q1.   The expansion joint are not support in the current PCF translator

A1. Support for Flex/Expansion Joints were implemented in PCF translator 1.0.0.24. Can You please use the latest release of PCF Translator. You can get the newer version of translator from ftp://ftp.bentley.com/pub/tools/fixes/autopipe/PCF_Setup_1.0.0.25.exe (Dec 2012).

Q2. The pipe is oriented 180 deg from original

A2. Before export to PCF from AutoPIPE, In AutoPIPE  Go to Tools> Settings > Isogen Settings

Change North arrow to +X then the coordinates matched exactly

Q3. Pressure and Temp are different from before to after, example: 10 deg & 100 psi converted to 0.0 deg  & 0.0 psi

A3. This is a limitation in AutoPIPE PCF Export, which does not write Pressure and Temperature and hence default values are used.

Q4. Pipe properties changed; wall thickness changed sch 160  changed to STD and Pipe material, from A335-P91 changed to A106-A

 A4. There is a limitation in AutoPIPE PCF Export could not correctly map the material and by default A106-A with STD wall thickness has been used. Adjust the map file as required to correctly map the material and wall thickness.

Q5. Extra support (V-stop)  added to the converted file at origin point with anchor.

A5. During first time Export to PCF. AutoPIPE write Anchors as a Support with SKEY 01AN and then on import this support component converted to an default support V-STOP. Manually delete V-Stop.

Q6. Flanges converted for the expansion joint are in the wrong location.

A6. This has been fixed in a newer version of the translator, upgrade to the latest version of PCF Translator, v1.0.0.32.

Q7. Tee SIF values are different (because of wall thickness issue above, Q4)

A7. Yes, proper schedule has not been exported by AutoPIPE in PCF. update PCF map file accordingly.

Q8 Bend radius is different

A8. Bend length is exactly same but after import from PCF the actual radius has been written instead of "LONG"

Load Combinations 

To review, modify or print new post processing combinations defined for the current model, select Tools> Combinations. The exact list of combinations will depend on the active load cases analyzed and the code
associated with the current system.

There are four distinct TAB GRIDS appearing on the Combination dialog:

1. Load Cases - All the analyzed static and dynamic load cases are displayed for each analysis set in the grid.

2. Code Comb. - The "Code Compliance" grid displays the combination set defined for piping code compliance.

3. Non-Code Comb. - The "Non-Code" grid displays the active load case combination set defined for any purpose other than code compliance

4. User Allowable - The "User Allowable" grid displays the allowable stresses to be used in the pre-verification and stress summary reports (ASME NB, NC, and ND codes only). 

NOTE: Press the help button on tthe Tools> Combinations dialog to see on line help details for each of the available features.

User load combinations

Once an analysis has been run, use Tools> Combinations to see all code and non-code combinations. AutoPIPE automatically combines the loads required to calculate piping code stresses. The "Other" category contains loads, which need to be combined by the user in order to analyze piping loads on equipment, piping loads on supports, and deflections under various applied loading conditions.

In order to evaluate cold (ambient) load and operating loads on supports and equipment, users may combine individual loads by using creating User-defined Combinations on the respective Code/Non-code comb. tab. For the combination name, choose something meaningful such as GR+T1, GR+T1+W1, etc. Typically, combinations for support and equipment loads are made using the Sum or Absolute Sum combination methods, although users may also use the SRSS combination or Resultant maximum methods to combine loads. On the same screen, select the loads to be combined to make up your operating loads (see Figures below).

 AutoPIPE 6.0 - 8.6

AutoPIPE V8i 9.0 and higher:

Non-Code Combinations Dialog

Code Combinations Dialog

After defining all your operating load combinations (GR+T1, GR+T1+W1, GR+T1+W2, etc.), it may be a good idea to create 2 more combinations for your MIN and MAX to more easily review support loads. Typically, engineers will use the MIN and MAX for their GR and all operating load combinations, ignoring the individual loads for Tl, Wl, W2, El, E2, etc. The MIN and MAX sort through all the selected loads and load combinations, and produce Minimum and Maximum results. The MIN and MAX results for support loads and deflections are a great tool for creating summary reports for the civil/structural engineer responsible for piping support design, saving significant man-hours in the review of worst case loads on supports and equipment.

For reporting purposes, users can minimize output by selecting

AutoPIPE 6.0 - 8.6: Tools> Non-code Combinations> 

AutoPIPE 9.0 and higher: Tools> Combinations> choose Code/Non-code Tab and press New Button.. 

select and de-selecting individual loads or combinations which do not need to be reported. After saving these combinations, the *.CMB file can be copied and renamed to another job, eliminating the need to create user combinations each time.

Please note that users can input a "-1" in the load factor field to analyze wind and seismic loads in the negative direction, e.g. GR+T1-WI, GR+T1-W2. This "-1" feature can be used if gaps or friction do not significantly affect piping loads at a particular support point or equipment connection. This negative direction can be included as part of your user load combinations, enabling users to evaluate results using operating load combinations with wind and seismic analyzed in both the negative and positive directions. AutoPIPE does consider gaps and friction only for the load directions chosen for the original analysis.

Questions and Answers:

• "Code Comb" tab Questions:

• "Non-Code Comb." tab questions

• General questions not covered by above WIKI pages

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

1. To automatically create operating load combinations for support loads and displacements:
   
        A. Select Tools > Combinations (Shortcut Key: CTRL + M)
   
        B. Click the option Add default NonCode Combination, as shown below: Combinations for load cases are also created by default but can be unselected for printing.
   
   

2. User Combinations as a Template for the Next Model
   
   User code or non-code combinations created in the program can be used as a template for other models with the same analyzed load cases. Copy the CMB file to the directory containing the new model and rename it to new model name.cmb, when the new model is analyzed the previously defined combinations will be available.
   
   AutoPIPE V8i 9.4.x has a new feature to save and import *.CMB files from a folder location regardless of file names of the original file. With the load Combination dialog screen open, press "Combintions Options" button, and select "Import Combination File" from the drop down listing (see help fro details on this topic).
   

3. Min/Max For Support Loads And Deflections

   Go to Tools >User Defined Comb. /NonCode menu. Give the combination name as e.g. Max Comb Combination method is 9 Sign Max (which ignores the sign of loads and deflections). Next, select the Case/comb for GR and your operating combinations, ignoring the theoretical loads of T1, W1, etc. Now check your output results for Support report, Deflections, or Restraint summary to see the new Max Comb results that you have created. See example below:

   HINT: Sign Max and Res Max (Resultant Maximum) are 2 common methods to evaluating maximums from other load cases or combinations. Other methods used are Min and Max.
   

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Problem:

Typical question / issues with AutoPIPE's Output "Mode Shape" Sub Report

Questions / Issues:

1. There is more information available under the following, File> Print> Reports> MODAL Output command not avaiable in the normal output reports.
   
   Thsi report contains 3 sections:
   
   Displacement 
   
   INDIVIDUAL MODAL CONTRIBUTIONS FOR RESPONSE SPECTRUM RESULTS
   
   
   Local Forces and Moments
   
   
   
   Relative Acceleration:
   
   
   
   
2.  For a model with a single segment on one axis (X-axis) with no bends, why are the R1 inertial forces in X directions {FX(Point 10) = 350.87 N and FX(Point 100) = 360.91 N}, are greater than zero, if the total modal captured mass in X direction is 0? 
   
   
   Answer:  When reviewing the output report the participation values may be 0.00 but the actual value is much smaller than can be reported.
   
   See the following procedure:
   1. Open the model
   2. Analyze the model
   3. Select Results> Grids
   4. Select Frequency Tab in the grid
   5. Select any cell in the Particip. Factor X column, note that the value is not 0.00 but much smaller, ex: -5.2860372e-011. AutoPIPE output report is not able to show such small values.
   
   Note: The anchor reaction is more for the model with higher cut-off frequency as it has higher level of discretization and thus able to capture higher modes better.
   
   
3. For a model with a single segment on one axis (X-axis) with no bends, Why for a very small cumulative modal mass of 2.0651929E-19 in X direction (corresponding to the 6th mode) such greater R1 forces values (FX=350.87 N and FX=360.91 N) have been obtained in anchors 10 and 100, while for a large cumulative modal mass of 7.9421875E+01 (corresponding to the 17th mode) lower R1 forces (FX=277.91 N and FX=271.42 N) have been calculated, accordingly?
   
   Answer: Look at the special modal report in ITEM #1 above to review the contribution of each mode and the missing mass correction in the total response. This can be reviewed at the pipe force and moments  and not for the anchor reactions which may be slightly higher than the pipe FX force due to contribution from the anchor. In addtion, see the following observations:
   
   
   
   
4. 2 models with exactly the same input except for ,modal analysis cutt off frequency, why are the first set of mode shapes NOT exactly the same?
   
   Answer: Changing the cut-off frequency when you have the automatic mass points option will lead to different level of discretization in the model. That should explain the differences in the frequencies. Rather, I would not expect the first 7 frequencies to be same  as the two models are no longer "equivalent" - because the level of discretization is not same. Higher the cutoff frequency, would be a higher level of discretization.
   

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!

Problem:

Typical question / issues with AutoPIPE's Output "Displacement" Sub Report

Questions / Issues:

1. I have created two models in AutoPIPE. The second model is the mirror model of the first model (I just rotate the model by 180 degree as per attached file). The wave and current that I applied for U1 and U2 are the same in magnitude but in opposite direction (+z and -z). My questions are:
   I had not received any model with your Service Ticket. Please resend your model for evaluation.

   I was expecting the results for Model 1 + U1 case and Model 2 + U2 are the same and similarly the result for Model 1 + U2 case is the same as Model 2 + U1 case. However, the results that I obtained look very different especially while I was checking the displacement based on GT1P1U1 & GT1P1U2 near the U Loop (refer to the attached file for detail). Is this normal? Isn't it two identical line will give identical answer?

   Answer: The results may be different. When running a wave analysis, the wave length is calculated based on the input parameters of the wave load dialog screen.  Wave length/phase has a significant effect on the load case results.

   When you rotated the model, each point may now be in a different location of the wave length or phase position. As a result, this would cause different results. 

   You can see what wave length was calculated by AutoPIPE: after completing a static Analysis, look at the Analysis Summary of the output report.

   Suggest, after rotating the model; align the model to cause the analysis to be performed at the same phase of the wave length.

2.  

See Also

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to
the "Comments" area below. THANK YOU!