Hello, I have a lateral support with spring support. The lateral support defined as guide support with 3mm gaps left & right, and a very large gaps up & down.(see image attached) The displacement per static seismic 1 case of the point (where the support is installed) is 0.661mm. Why the force on the support is 17797N per seismic 1 case in X direction if the displacement of the point is less than the defined gap?(3mm) I would expect a zero force in X direction. Thank you
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Forum Post: Loads on guide support while the displacement of pipe is smaller than the gaps defined
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Forum Post: RE: Loads on guide support while the displacement of pipe is smaller than the gaps defined
Hello MikeNi, Without looking at your model, sounds like you are performing a non-linear analysis and you are looking at the individual load case. This is most likely a load sequencing issue. Please see the following WIKI page: communities.bentley.com/.../8403.non-linear-load-sequencing.aspx In addition, recommend you change the guide to an incline support with the correct gap. Regards, Mike Dattilio Bentley Technical Support Analyst Web: selectservices.bentley.com Create your Service Request online! Log in to SELECTservices Online via selectservices.bentley.com and then go to My Support Account Service Request Manager. You'll have the ability to create a new Service request, view all Service Requests created by you or anyone else in your company, and view statistics on previous requests.
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Wiki Page: PCF Translator Issues for AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: import Subarea: Original Author: Bentley Technical Support Group PCF Translator Notes: A. The PCF translator can import almost any type of PCF file created by other 3D cad applications (i.e. SmartPlant, AutoPlant, SoildWorxs, Catia, Plant3D, CADworx, etc..). If there are complications please log a help desk ticket. Start the PCF translator by using one of the following: 1. From with in AutoPIPE, select File Import choose any one that has (PCF) at the end of the name. 2. Select Start Bentley Engineering AutoPIPE Translator PCF translator PCF translator program After the PCF translator application opens, see online help for details about the dialog. B. PCF file does not store Pressure or Temperature settings, to be sure library data is retrieved for pipe properties, thermal expansion, hot modulus, hot allowable, etc, after importing a model suggest the following steps: select Tools Model Options General change Ambient temperature to a different setting, press OK button, after the model data has been refreshed, reset Ambient temperature back to the original setting. C. Per "SmartPlantToAutoPIPETranslator_UserReference.pdf" Rev.05, Section 6, the PCF translator can be run from the command line. However, the information was added to the PDF file before the actual functionality was added to the program. As an official statement, the PCF translator cannot be run from the command or be apart of the Automated System Processing feature in AutoPIPE. See AutoPIPE on-line help "Automated System Processing" for parameter switches supported by the program. Also, see AutoPIPE V8i 9.6 and higher Analysis Batch File Generator. D. CAE development team has released a new PCF translator v.01.00.00.36 to be included into AutoPIPE V8i 09.06.01.xx and higher. if you would like a copy before the new full version release in 2014, log a service request mentioning this note. Comments, Questions, and Answers: PCF Translator FAQ & Troubleshooting Imported NTL Errors from PCF Translated File PCF Translator Logged CR / TR Issues PCF Translator Version and Features 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!
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Wiki Page: Modeling Vessel / Nozzles in AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Modeling Subarea: Original Author: Bentley Technical Support Group The following section will contain questions and answers pertaining to modeling vessels and/or nozzles in AutoPIPE. ATTENTION: Please see the following AutoPIPE help section: Help Contents Contents Tab Modeling Approaches Modeling Approaches Vessel and Nozzle Item #1: Could you please advise how to properly model a nozzle at the dished end. We have modeled using nozzle flexibilty option (using "spherical" in flexibility method) Length = head thickness. Then we triedwith the "user" input in the flexibility method using the stiffness values from the "spherical" option but the results are completely different between using "spherical" and "user" selection. Answer: As you already know the nozzle flexibilities calculated for a Spherical head are Radial and Bending stiffness of the nozzle, where User flexibilities fields are Radial, Circumferential, and Longitudinal stiffness of the nozzle. In the background, AutoPIPE use flexible joint elements to model a nozzle. The stiffness calculations for Nozzles connected to cylindrical vessels are more sensitive to diameter of the pipe. The difference with your modeling is to be sure that the Radial direction is the same for both User and Spherical stiffness's, and that Spherical Bending values/directions matches the User's Cir & Long values/directions. Consider the following, if you are using the flexibility method = User, what direction is Rad, Cir, Long given global X, Y, & Z. In AutoPIPE a vessel is modeled as a pipe component. So the program does not know which direction a nozzle element Rad, Cir, Long is until you specify the direction of the vessel. Direction of vessel = Global Y, that means Long. is Global Y and Rad. & Cir are set to Global X or Z. Direction of vessel = Global X or Z, That mean Rad. is set to Global Y, Long. is set to Global X or Z and Cir is set to Global axis left over. Again, by defining the nozzle element vessel direction, you are setting direction for Long and consequently Rad and Cir. Item #2: What is the best method of evluating a nozzle load to see if they exceed manufacture stress requirement limits? Answer: Insert a Reference Point to Evaluate Equipment Loads Use the Insert Xtra data Reference Node feature to define reference points to evaluate loads at vessels or rotating equipment. Works in either Global or local coordinate systems. So anytime the nozzle is at a skewed angle to the vessel and the allowable loads at the nozzle are given relative to the nozzle axis then use the local coordinate axis system. You can define multiple "Reference Points" at any point. HINT : Useful for evaluating in-line pump nozzles and manufacturer stated limits on vessels or equipment. Item #3: How to model Vacuum Jacket on pipe connected to a Nozzle? Answer: Please see the following AutoPIPE help section: Help Contents Contents Tab Modeling Approaches Modeling Approaches Nozzles, Model 1: Cylindrical Vessel Surface. Using this model as a starting point, follow the instructions to model this example. Note, understand the modeling here, the flexible joint represents the wall thickness of the vessel. Therefore unless the vauccum jacketed pipie continues inside of the vessel, select Node point A03 as the starting point of the vacuum jacket. Select Pipe range from A00 to A03, Select Copy command / icon, Select Base point: A00 Besure the active point is A00 and select Paste command / icon, Select Segment B, all. Modify Pipe Properties Over Range PipeID =14"std, pipe OD = 14", press OK button o accept Note: Pipe segments are restrained by Pipe supports, Soil suports, etc... Pipe segments can be overlapped with out warning. It is the user responsibility to review any interference with-in AutoPIPE or to export a model for clash detection by another program. Example, at this point select segment A, notice how it potruse through the pipe at the elbow locations. Select the large pipe elbows and change from Long radius to short radius. Next, in order to connect the larger jacket pipe to the smaller internal pipe, select node point A00, Insert Beam To Point J = B00, section Id = 0 - ridgid Repeat step to connect Node point A03 to B03. Add as any addtional node points for support spiders for the interanal pipe connected to the Jacketed pipe. Example: Select Node point A01, insert Run Dx = 3 ft, press OK button, creates node point A05 Select Node pont B01, insert Run Dx = 3 ft, press OK button, creates node point B04. To support the internal pipe (seg A) from the jacket pipe (seg B), select node point A05, Insert Support type =Vstop, Connected to point = B04 Vstop A05 is no supported by pipe node point B04. As B04 moves so does the support holding A05. See Jacketing piping WIKI page for more details on this topic. Item #4: Modeling a Nozzle per WRC 297? Answer: The following fields of data are available when WRC 297 is selected as a Flexibility Method on a nozzle dialog screen: Enter in values for L1, L2, and Direction of vessel axis to calculate the nozzle flexibility. Copied from the On-line help: L1 = distance from the center of the nozzle to either vessel end or to the face of the nearest internal stiffening attachment (e.g., ring). L2 = Enter the distance to the other end of the vessel (or nearest internal stiffening attachment in that direction). Meaning, measuring from the center of the nozzle in one direction along the axis of the vessel to a point where the vessel end or vessel internal stiffener ring, enter the value as L1. Repeat the same measurment in the opposite direction along the vessel to a point where the vessel ends or vessel internal stiffener ring, enter the value as L2 (note, L1 and L2 are interchangeable values with regards to the nozzle flexibility calculation, see online help "Nozzle Flexibility Calculations" for complete details). Note: When looking at the Nozzle Stiffness values on the dialog screen be sure to read the dialog text "Nozzle stiffness (E6):". The (E6) means that the value in the fields below are multiplied by E6, with the given units. Example, on the dialog screen Rad = 3.1223 lb /in, but in the output report it is printed as Krad=3122285.75 lb/in. Both values and units are correctly printed. Item #5: Questions: Can you provide more details on the Nozzle dialog fields, Length and Thickness? Answer : The Nozzle element is used to take credit for the flexibility of surrounding wall where the nozzle piping is attached. Therefore the modeling concept is that the expansion joint is used to represent the wall thickness and flexibility of the vessel / container where the nozzle is mounted. The Nozzle element length should not be equal to the distance from the vessel / container wall to the a mating flange face. From AutoPIPE online help: Length: Enter the length of the vessel shell wall. Nozzle length is not used in calculated the nozzle flexibility (which is really the vessel shell flexibility). The length defines a flexible joint to which the nozzle flexibilities (as calculated by AutoPIPE) are assigned. Vessel Radius/ Thickness: Enter the outside radius (or half the actual diameter) of the vessel and the thickness of the vessel wall in these two fields. For new user, there remains a lot of confusion around the Nozzle dialog entries for Thickness and Length. Simply put a nozzle element is modeled as a Flexible joint, as shown in the image below. The Nozzle Length field specifies how long the flexible joint being modeled will be (distance between A03 - A04) in the program. Aka, the physical length of the Flexible joint in the model. Again, the Length is usually equal to the wall thickness of the vessel / container where the nozzle is attached too. The Thickness value is used by the program to calculate the respective nozzle stiffness values that will become input into the flexible joint dialog screen (ex, calculated values for: Axial, Shear, torsional, bending stuffinesses). Again, Length and Thickness are 2 different fields used for 2 different reasons; one modeling and the other calculations. Under most circumstances Length & Thickness will be the same. However, be careful when entering these values, always look to see what units are being used. In English units, Length is entered in FT (mm) , where Thickness is entered in INCH (mm) . 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!
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Forum Post: RE: User SIF for complex geometries
Thank you. The problem is that codes like ASME B31, EN13480 don't provide formulas for reducing tees and thus what we have in AutoPIPE seems to be inacurate, 'fortunately' for AutoPIPE this is due to the reason the code is kind of improper. I wonder if there is a chance Bentley gets kind of solution for that, what would be a good step forward, in my opinion.
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Wiki Page: Stress Iso Troubleshooting Tips for AutoPIPE
Comments, Questions, and Answers with AutoPIPE Stress ISO. In addtion to the "StressISO_Troubleshooting.pdf" document found on your hard drive, see the following 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 troubleshoot 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, etc..). Sometimes a run of pipe is broken into multiple segments on the same run of pipe. Best practce for when creating models for export to Stress ISO, reduce the number of segments to as few as possible, by using Edit Segment Join command at run node points that are common between 2 segments. Another great tip, with a complicated model use the following feature: Select Connected segments choose only one box to highlight a connected series of pipe. A limitation to the Alias Stress Isogen is that it cannot process 2 or more 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" or "se Selected range" check box is checked ON. Note: If using example technique: "Modeling a "dummy leg" as a structural member or a pipe", again stress Iso cannot generate the dummy support because it is considered as a disconnected segment. 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 to add leg information.. 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 1. Start Menu Run 2. Type "cmd" 3. Press "ENTER" or "Return" keyboard key d. Using the POD.dll filename and path, call regsvr32, i.e. at the command-line prompt, type: 1. regsvr32 "C:\Program Files (x86)\Common Files\Bentley Shared\Plant V8i\Isogen\pod.dll" 2. Press "ENTER" or "Return" keyboard key e. You should see a regsvr32 window, confirming success: Close it. 1. RegSvr32 2. 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 fill 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: 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 DRAWING ERROR 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. Annotations are not saved with the model: I use to insert Engineers comments on the Stress Isometric, but after closing AutoPIPE all information inserted in Annotation are lost and I have to insert again. Is there a possibility to save information in Annotation for example to external file or to model AutoPIPE? Answer: This functionality may not be available in the previous versions. However, using AutoPIPE V8i 09.06.00.15 and Higher, use the following procedure: Steps to repeat: 1. Open the model in AutoPIPE 2. analyze the model 3. Select File Save Stress Isometric Provide a drawing name, location, and press SAVE button. 4. On the Stress Iso Options screen press the Annotation button in lower right corner of the dialog screen. 5. Add a new annotation Point, Note, check the box for PLOT, and press OK button 2x to create the stress iso. 6. View the Stress iso. 7. Back in AutoPIPE, select File Save, then File Close, and finally press File Exit. 8. Restart AutoPIPE, and reopen the same model. 9. Perform an number of commands and then repeat steps 2-5 from above, Note: the annotation from the previous steps is still present. 17. Worst case Scenario in data tables: When creating a Stress iso the data table do not show the worst case scenario. why? Answer: The issue was caused by changing the keyboard to a different language (i.e. French) settings instead of using English settings. 18. 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!
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Wiki Page: Modal Analysis - AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers: Note: Please see the following AutoPIPE help section: Help Contents Contents Tab Reference Information Analysis Considerations Modal Analysis for complete details. Comments from Mitch Sklar training class on Modal Analysis: #0 Natural frequency and mode shapes are property of the structure and depend on the mass and elasticity. They describe the tendency of the structure to vibrate when subjected to dynamic loading. Number of frequencies and mode shapes with which a structure can vibrate depends on the number of mass degrees of freedom in the structure. Mode shapes describe relative displacement of the structure (mass normalized). Number of mode shapes and frequencies required depends on the frequency of the applied load. #1 The captured modal mass percentage tells how much of the response is attributed to a particular mode and also tells on the mode orientation (X,Y or Z). The sum of modal masses should be 100% if all modes are counted. But since many modes are not counted, the sum is less than 100 and hence the importance of the ZPA and missing mass options for dynamic analysis. #2: Modal analysis advantage is that it can give good results by analyzing few modes. But that is not true for all systems. Seismic / Earth quake: Earthquake loading typically do not have frequencies above 50 Hz (most often between 0 and 33 Hz ) and so setting cut-off frequency to 50 or 33 Hz and including missing mass or ZPA will usually give satisfactory results. Some people like to make sure the captured modal mass is at least 75% or even 90%. For Response Spectrum analysis, in some modal analysis 60% Participation is not bad for earthquake analysis as long as the cut-off frequency is above 33 Hz and both "Include missing mass" and "ZPA" options are enable. Fluid Transient: Water hammer is usually a high frequency load, typical cut-off frequencies range from 150-400 Hz. Equipment Machine vibrations, the analysis is often done up to 12 or 20 harmonics of the reciprocating equipment. For 300 rpm, first harmonic is 300/60=5Hz. So 20 harmonics would be 20x5= 100 Hz. AutoPIPE provide the option to perform a modal analysis by a. Cut-off frequency or b. Number of mode shapes. Using Cut-off Frequencies, the frequency range of the modes should always cover the frequency content of the loading function and in some cases you need to analyze for all the modes by including a large cut-off frequency (e.g. 1.E20). This is usually done to capture support reactions in the absence of using ZPA or missing mass correction to correct for these unused higher modes. Using Number of modes is just another way to limit the frequencies, recommend to set the number of modes to 999 to capture all modes up to a cut-off frequency. It is also important to look at the captured modal mass percentage in the frequency report and analysis summary. It is good to have about 75% or more of the mass captured if possible. The more modes you have the more captured mass will be. Also recommend using missing mass and/or ZPA options to correct for all higher modes that are not included in the analysis. #3: The usual procedure for determining how many modes are sufficient is to extract a certain number of modes and review the results; then to repeat the analysis while extracting 5 to 10 additional modes, and comparing the new results to the old. If there is a significant change between the results, a new analysis is made, again extracting 5 to 10 more modes above those that were extracted for the second analysis. This iterative process continues until the results taper off, becoming asymptotic. The fact you are getting different results for different cut-off frequency indicates that your loading have higher frequencies. #4: Regardless of the mechanical cut off frequency used for span calculations, AutoPIPE modal analysis cut off frequency should always exceed the vibrational and forcing function frequencies expected. For example if you are interested in harmonic forcing functions at 88 Hz, I would use 1.5x88 or 2x88 Hz as the cut off frequency. As usual, every time you set the cut off frequency for modal analysis, you need to set the cut off frequency for mass discretizations in Tools/Model Options/Edit. Never limit to certain mode number and always maximize number of modes to 999. In general low compressor speeds requires forcing functions up to 100 Hz or 200 Hz cut off frequency. Higher compressor speeds requires higher harmonic frequencies and hence higher cut off frequencies. #5: AutoPIPE lumps the mass of the pipe, components and contents, etc. at the associated node point. This assumption yields a diagonal mass matrix with no mass coupling terms. There are three mass degrees of freedom per node. Rotational mass is ignored, except for points with eccentric weights #6: AutoPIPE uses a subspace iteration method from SAP IV for solving mode shapes. SAP IV is a general purpose finite element analysis program for linear structural analysis originally developed at UC (Berkeley). AutoPIPE does account for pressure stiffening of bends, but not tension stiffening in modal analysis. In addition , AutoPIPE finite element solver does consider transverse shear stiffness. Question #1: Output report, subsection - Frequency found the Participation Factor-X =-0, Captured Modal Mass-X = 0 and Cumulative Modal Mass-X = 0, for all calculated natural frequencies, but in anchors there are existing forces greater than 0, FX(Point 10) = 350.87 N and FX(Point 100) = 360.91 N. How can this situation be explained? Answer The model was found to be a single segment, 100m long on the Global X axis. The pipe has no bends, expansion loops, or is modeled on any other axis except Global X. As a result the participation factors were reported in the output report as 0.00 for the same pipe axis (Global X), however the actual value may not be 0.00. AutoPIPE is only able to report a number with 2 significant digits. use the following procedure to validate the actual value calculated: 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. Suggestion, confirm actual value calculated using the results grid. Question #2 Given a model with a single pipe, modeled between 2 anchors on the Global X axis, the calculated inertial forces and moments in the TEST1 model are FX, FY, FZ (where, FZ=2258.35 N), MX, MY (where, MY=5588.1 N-m) & MZ, for both anchor points 10 and 100, are significantly lower than the inertial forces and moments FX, FY (where, FY=3030.55) FZ, MX, MY (where, MY=8585.51N-m) & MZ calculated in TEST2 model, accordingly. The only difference between these 2 models is that modal analysis cut of freq = 66 hz for TEST1 & 120 hz to TEST2. Thus, even if more frequencies and their associated modal masses are obtained in the analysis TEST2 model (Fr eq = 120 Hz and 12 modes obtained), the lesser inertial forces and moments values are obtained in anchor points 10 and 100, com paring with TEST1 (Freq = 60.2 Hz and 6 modes obtained), respectively. So, how can this situation be explained? Answer : One issue was that more than a different value for modal analysis was found between the 2 original models. To be absolutely sure that the models are identical, open the 1st model, saved as 2nd model name, and make the changes as required, ex: change modal cut-off frequency from 33hz to 120 hz. To answer the question, might find that 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. Question #3 Analyzing the 2 models TEST1 and TEST2, we observe that for the first 6 vibration modes (Mode No 1 to Mode No 6) each calculation model gives different values for the first 6 calculated frequencies, as well as for the first 6 Participation Factors (in t he X, Y and Z directions) and for the first 6 Captured Modal Mass (in the X, Y and Z directions) respectively. Obviously, the first 6 Cumulated Modal Masses (in the X, Y and Z directions) are also different in the 2 models (TEST1 and TEST2). Furthermore, the first 6 Shape Modes from each model are different. How is this possible, given the identical conditions in the calculation models - except for the different Cutoff Frequencies (66Hz and 120 Hz, respectively)? Answer : One issue was that more than a different value for modal analysis was found between the 2 original models. To be absolutely sure that the models are identical, open the 1st model, saved as 2nd model name, and make the changes as required, ex: change modal cut-off frequency from 33hz to 120 hz. Knowing the files are now identical with exception to changes made, performed a model analysis and Static analysis on both models. Changing the cut-off frequency when you have Tools Model Options Edit Mass points per span = A option enabled will lead to different level of discretization in the model. That should explain the differences in the frequencies. Another words, not expect the first 7 frequencies to be same between the two models as they are no longer "equivalent" - because the level of discretization is not same. The higher the cutoff frequency, the higher the level of discretization. Question #4 I am confused on the interaction of the Cutoff Frequency and Maximum Number of modes? It seems the Cutoff Frequency under the Model Options is always superseded by the values declared under the Dynamic Analysis? When/Where does the Cutoff Frequency under the Model Options control? Answer: Edit Model options .. this cut off frequency is used to calculate the optimal mass span length only From Online help: Question #3 Are there any (practical ) maximum cut-off frequency values, I tried 100,000 and the following occurred:? Answer: See the following for suggestions to this error message : click here Question #5 Estimate the cutoff frequency for my dynamic water hammer analysis? Answer: The maximum frequency cutoff can be estimated from: SQRT (E/p)/L, Where: E is the modulus of elasticity of the pipe material, p is the density of the pipe material L is the length of a single pipe element in the primary run that is to have accurate stresses computed due to the passing of the water hammer originated acoustic stress wave. Example: Calculation of the maximum cutoff frequency for between 2 elbows (node point 45 & 75) with 20-foot pipe lengths is given as follows: When performing a modal analysis on the piping system, impulse loading such as water hammer may have high excitation frequencies even as high as 200-300 Hz. For small piping systems, the extraction of high frequency modes is relatively fast and will more accurately predict local dynamic responses than the static correction methods. Question #6 What is considered to be low / high frequency values? Answer: There may be no such clear cut separation between high and low frequency phenomenon. Some may suggest: Low frequency ( 300hz) high frequency( 300hz) Question #7 From Modal Analysis Theory, that modal analysis is performed as a linear analysis but nothing is mentioned about if Buoyancy is considered during the frequency calculations. We did consider added mass in our calculations but it looks like AutoPIPE is using 'weight in air+added mass' instead of 'submerged weight + added mass. Could you please confirm? Answer: For submerged pipe, the buoyancy "Added mass coeff" increases the mass of the pipe by Coeff x Mass of displaced water during vibration. So you should expect the frequencies to be lower. Again, the mass of the pipe is not affected by buoyancy. Question #8 I would like to know the advantage of 'discretizing' the model with mass points. Why to discretized? Answers: It improves accuracy for the analysis. Please see the following AutoPIPE help section: Help Contents Contents Tab Bentley AutoPIPE Frequently Asked questions, scroll down #77. Question #9 What we wanted to do was to apply anchor displacement and pre-stress the pipe before performing modal analysis i.e. check the vibrations in its deformed operating condition? Answers: The modal displacements and rotations describe the set of natural "shapes" or "patterns" of the system when vibrating (no external load). The model shapes depend on how the system's mass and stiffness are distributed. Therefore, at this time, AutoPIPE V8i 09.06.xx.xx and lower cannot consider anchor or support displacement in conjunction with modal 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!
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Wiki Page: AutoPIPE FAQ - Limitations
First review AutoPIPE limitation in the online help: Please see the following AutoPIPE help section: Help Contents Search Tab enter "Save Defaults" (include the quotes), press List Topics button, double click on the selected topic from the list provided to see more information. Item #1, Question: What is the maximum pipeline length we can model in AutoPipe? Answer: You can model any length of pipe line as long as the model database does not exceed the 10,000 node point limitation and the coordinate location values. Item #2, Question: Is there a limit on the number of digits for the coordinates in Autopipe? We have a project that has the following plant coordinates, 202094'4.875", that we want to use in Autopipe. Answer: Yes there is a limit. On the Input grid's, point tab, Global X, Y, & Z values are limited to input 8-9 place values regardless of the value that can actually be entered (max =15 place value). As a general rule of thumb, suggest trying to restrict this field to about 8-9 values (example 1234.6789, or 123456.89). Another option, change the unit of measurement used for coordinate in the respective Unit input file (*.UNT) specified on Tools Model Options General Unit Input. Instead of using Feet use yards, mile, furlong, etc..
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Wiki Page: Re-associate AutoPIPE's *.DAT file extension to execute the program when double selected
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: installation Subarea: Original Author: Bentley Technical Support Group Problem: After installing a newer version of AutoPIPE on a machine, I am unable to update the file association so that the newer version opens the files when double-click a *.DAT file from a folder location. I tried setting the Windows 7 file association as instructed by Microsoft, but that does not fix the issue. How to resolve? Answer: By default the application should not be started by double clicking a file from windows explorer. The application should be properly started and the files opened using the File open command, or Open Icon button. If there is something wrong with the file association, please contact your IT department for their instructions to fix the situation. The following is one set of instructions to fix file association issues, to be used at your discretion: 1 . Install a very small application called TYPES ; a 200 KB (.net based application) http://izt.name/apps/types/ Types allows you to customize the way Windows handles different file types: set program associations, change icons, context menus and other properties 2. Press the Download hyper link on the web page. 3. Select the option to " Run " the application. Depending on your internet settings the following may appear: Again, select RUN . You may need to get your IT department involved if permission to install becomes and issue. 4. The following screen will now appear, recommend to select Control Panel only 5. After pressing " Install " button, this will install a small application in the control panel name: " Types ". Press the close button on the dialog. 6. Go to the Control Panel , search for an app called " Types ", and open it. the following will be displayed. 7. Search for DAT in the listing as shown above. 8. Double click on it. a. Class tab: select Application\AutoPIPE; b. Action Tab:select OPEN in the field provided and confirm autopipe.exe location. If not correct, select correct location from drop down list. Images are shown below: (close the dialog by pressing X in the upper right corner). 9. Close TYPES application and confirm the application can be started by double selecting the DAT file from a folder location. DAT, .DAT, AutoPIPE, Open, associate, re-associate 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!
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Wiki Page: Piping Codes Enhancements for AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Enhancements Subarea: Original Author: Bentley Technical Support Group Select one of the following piping codes to see the enhancements that have been logged for inclusion into a future version of AutoPIPE: Note: if an enhancement has not already been added to the program, log an enhancement request with the respective CAE number. The more requests per an enhancement, the quicker the CAE development team will add that feature to the program ASEM B31.1 Power Piping ASME B31.3 Process Piping ASME B31.4 & Chpater IX Liquid Transportation Systems for Hydro-carbons, Liquid Petroleum Gas, Anhydrous Ammonia, & Alcohols Offshore Liquid Piping Systems ASME B31.8 & Chapter VIII Gas Transmission & Distribution Piping Systems Offshore Gas Transmission ASME B31G Manual for Determining the Remaining Strength of Corroded Pipelines ASME BPV-III-1-NB, NC, & ND Boiler & Pressure Vessel Code, Rules for Construction of Nuclear Power Plant Components Division 1, Subsection NB, Class 1, 2, & 3 Components JSME S NC1-PPC Rules on Design and Construction for Nuclear Power Plants, Class 2 Piping BS806 Design and Construction of Ferrous Piping Installations For and In Connection with Land Boilers SPC Swedish Piping Code, Code for Piping in Stationary Plants (Stress Analysis - Method 2) TBK5-6 Norwegian Pressure Vessel Committee, General Rules for Piping Systems STOOMWEZEN (D1101) Dutch Piping Rule D1101 of the Rules for Pressure Vessels CAN/CSA-Z662 & section 11 Canadian Standards Association, Oil and Gas Pipeline Systems Canadian Standards Association, Offshore Steel Pipelines DNV enhancements for AutoPIPE Norwegian Piping Code, Rules for Submarine Pipeline Systems MITI501 Technical Standards for Construction of Nuclear Power Plant Components - MITI Notification No. 501 KHK Level 1 & 2 KHK E 012 Japanese Piping Code for Seismic Loads, Level 1 & 2 EN13480 EN 13480 European Standard for Metallic Industrial Piping RCC-M French Piping Code SNCT French Piping Code SNiP Russian Trunk Pipelines Code BS7159 Design and Construction of Glass Reinforced Plastics (GRP) Piping Systems for Individual Plants or Sites ISO 14692 Petroleum and Natural Gas Industries, Glass-Reinforced Plastics (GRP) Piping General General Piping Code CSA 289 Canadian Standards Association, General Requirements for Seismic Qualification of CANDU Nuclear Power Plants BSI PD8010 British Standards Institution PD 8010-1: Code of practice for pipelines - Part 1: Steel pipelines on land PD 8010-2: Code of practice for pipelines - Part 2: Subsea pipelines PD 8010-3: Code of practice for pipelines - Part 3: Guide to application of pipeline risk PD 8010-4: Code of practice for pipelines - Part 4: Code of practice for integrity management PD 8010-5: Code of practice for pipelines - Part 5: GUIDE TO OPERATIONALPRACTICE CAE-CR-3582: Apply 2 or more piping codes in the same calculation Fixed version: TBD Workaround: Suggest analyzing the model or creating multiple models each one using a different piping code. Then select, review, and print the output for just the applicable run of pipe per the required code. Example, run analysis using ASME NB Nuclear piping code, select the node points that must be analyzed per ASME NB code, create an output report "Limit results to highlighted points", and repeat above steps after selecting a different piping code, etc... 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!
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Wiki Page: Non-linear Load Sequencing Explained
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Analysis Subarea: Original Author: Bentley Technical Support Group Whenever a static analysis load set includes Gaps/Friction/Soil it is calculated using a non-linear analysis. As a non-linear analysis, individual load cases (i.e. Gr, T1, P1, E1, W1, etc..) are applied one at a time in a sequence. This specific sequence does affect the calculated combination results (see AutoPIPE online help for more details). For example, by default, occasional load cases like Earthquake or Wind are analyzed after Pressure cases, that are applied after Thermal loads, that are applied after the initial load case Gravity. Wind hitting the operating position of the piping may calculate different support loads than earthquake or wind loads calculated just after GR (wind hitting the ambient position of piping). When perfoming a nonlinear analysis, select Loads Static Analysis Sets and check boxes in the "Non-Linear" columm or enable Gaps/Friction/Soil inside of an analysis set . To define all non-linear options, modify the analysis set, and check the option "Gaps/Friction/Soil", Click OK and the next screen appears, see online help for details on this dialog screen. For more complicated load sequence, uncheck the "Use Default Sequence" box to modify the Load sequence and press OK button as shown below: Attention: 1. Please see the following AutoPIPE help section: Help Contents Search Tab enter " Understanding Load Sequencing " (include the quotes), press List Topics button, double click on the selected topic from the list provided to see more information select the hyper link for "Understanding Load Sequencing". 2. Open the PDF file directly from the AutoPIPE folder, search for "Load_Sequencing.pdf" or "Non_Linear_Load_Sequencing.pdf" on your computer. 3. Additional documents found on the WIKI sites: a. Non-linear_Guide_explained b. Discussion of AutoPIPE Advanced Non-Linear Analysis Engine c. Understanding Non-Linear Load Sequencing d. Treatment of Support Friction in Pipe Stress Analysis e. Nonlinear Effects in Piping System Analysis f. Improved Iteration Strategy for Nonlinear Structures g. Defining Nonlinear Wind Load Case Additional Information: The Non-linear method is a sequence of applied load cases as defined on the initial states dialog (shown above). For example, a guide support with 0.2" gap left / right, non-code combination GT1E1, is analyzed by: 1. First applying the Gravity weight load case to the system and calculating the deformation based on modeled restraints. 2. Then the thermal expansion load case (T1) is applied to the deformed model, and again a new deformation is calculated. 3. Finally, as indicated above, occasional load case E1 is applied to the deformed model, and the final deformation is calculated. In the output report only look at the operating conditions (i.e. GT1E1, GT1W1, etc..) and not the individual load cases (i.e. Gr, T1, E1). The individual load case moments may be larger than than a gap support allows but when added in a combination the results are correct. . In 2009, ASME published that there are generally 3 methods used by most computer programs for stress analysis, 2 of which "General Straightforward Approach" and "Algebraic Subtraction Approach" (used by Caesar II) were found to produce inaccurate results. Only "Operating Condition Approach" used by programs like AutoPIPE, FE Pipe, Ansys, Abacus, Simplex II. that meets the code philosophy and requirements. Example: Example: Summary: When support conditions change, superposition leads to inconsistent and less accurate results. Using AutoPIPE's method of loading sequences is much closer to reality and is used by the best known programs such as ANSYS finite element, FE -PIPE, ABAQUS, etc. Reference: The non-linear technical paper refered above: https://www.asme.org/products/books/pipe-stress-engineering 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! Gaps/Friction/Soil
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Forum Post: RE: Piston type pump pulsation
The best way is to simulate the acoustic model using Bentley PULS. It will calculate the shaking forces and can export these using harmonic HMF file. Otherwise you would need to assume some pipe harmonic forces at elbows. Sometimes you need to change the load frequency to match pipe resonance for worst scenario.
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Forum Post: RE: Loads on guide support while the displacement of pipe is smaller than the gaps defined
When looking at reactions you need to look at actual nonlinear cases that you solved for. The load combinations generated by the program are usually consistent with the load sequence. For seismic cases, AutoPIPE never solves for E case alone. It either solves for GR+E1 or GR+T1+P1. So you will need to look at the cases generated by AutoPIPE for consistent displacements and reactions.
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Forum Post: RE: Loads on guide support while the displacement of pipe is smaller than the gaps defined
As suggested by Mike, it is best to use an incline support (2dir) support instead of 4dir guide support when you have restraint along one line only. This is especially important when using dynamic analysis as AutoPIPE sets all gaps to zero for modal analysis and hence activates a non existent support.
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Wiki Page: PULS program stops working
Applies To Product(s): PULS, Version(s): all Environment: N/A Area: Program Crash Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers when PULS stops working: Item #1: The program freezes or stops working when trying to display any results plots: Answer: Confirm the RPM setting is not too fine of detail for the plotting function to handle. Example: Found the current setting fro plot step = 3, change setting, RPM step = 5. The plot should now be displayed. 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!
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Wiki Page: Bentley PULS
Topics under the heading should be based on: Bentley PULS Op1, Op2, or Op3 Installation Error Messges Modeling In PULS Calculations in PULS Results in PULS PULS program stops working
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Wiki Page: Reports - AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: reports Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers on AutoPIPE output reports: Item #1. Results Interpretation Be sure to review AutoPIPE's online help: Help Contents Contents Tab Reference Information Results Interpretation This appendix explains how to interpret AutoPIPE's output report results. The coordinate systems used for the results presentation are particularly important, and are listed first. The output sign conventions for the different result types are then described. - Coordinate Systems - Total vs. Incremental Loading - Pipe Displacements - Pipe Forces and Moments: Global Option - Anchor Forces - Support Forces: Hangers and V-stops - Support Deformations: Hangers and V-stops without Gaps - V-stops with Gaps and Friction - Hangers and V-Stops with Imposed Displacement - Two-Point Hangers and V-Stops - Straight Pipe Forces and Moments: Local Option - Support Forces for Guides and Line Stops without Gaps - Support Forces: Guides & Line Stops with Gaps & Friction - Two-Point Guides and Line Stops - Curved Pipe Forces and Moments: Local Option - Support Forces for Skewed Supports - Support Forces for Tie/Link Restraints - Beam Member Forces - Dynamic Support Forces Item #2. Analysis Sub-reports See the following hyperlinks for issue on the respective Analysis Output sub report: Command: Analyze model Results Output Report: - Displacement - Support - Restraint - Forces & Moments - Code Compliance - Stress Summary - Frequency - Mode shapes - Equipment - Soil - Bend Angular Distortion - Stress Indices - Tee Plastic Strain - Beam forces - General stress - Preliminary Stress - Accelerations - Flange Summary - Model listing - Analysis summary - Steam Relief - Reference Loads - Fatigue - Result summary Item #3 Component Data Listing: See the following hyperlink for issues on the respective Component Data listing (aka Model Input Listing) report:Command: Tools Model Input listing. - Extended Component (Point in v6.1) - Coordinates (Component in v6.1) - Pipe Properties - Material Properties - Material Allowables - Temperature & Pressure - Beam - Forces & Displacements - Thermal Anchor Movements - Seismic Anchor Movements - Center of Gravity - Earthquake Scale Factors - Design Temp and Press - Soil Properties - Load Summary - Support - Bend - Tee - Valve - Flange - User SIF - Reducer - Rigid Pipe - Reference Points - Gross Discontinuity Stress - Segments Data Item #4: Can AutoPIPE print the Output reports to excel or .csv? Answer : We apologize for the inconvenience, however AutoPIPE cannot print its reports directly to MS word or MS Excel. Reports are currently written to the following files: *.OUT, *.HGR, *.RPT. These file can be opened by any text editor (i.e. NotePad, Ms WORD, ect..) . Also, AutoPIPE can export both the Input gids and Results grids to a database file (*.MDB), for manipulation into customized reports. This enhancement has been logged under CAE-CR-345: Add option to generate reports as EXCEL & WORD files. Items #5: AutoPIPE Results Grids or Output Reports are found to be Zero (0.00) or Blank Item #6: What is the meaning of + and - (+/-) Node points in AutoPIPE results? Answer: Please see the following AutoPIPE help section: Help Contents Contents Tab Reference Information Results Interpretation Pipe Forces and Moments: Global Option Item #7: Can we select a number of specific node points, pipe supports, etc. to report in the AutoPIPE result print out? Answer: Using any of the various method of selection, select the node points, supports, bends, etc. that are to be printed in the output report. After the selection process has been completed, perform a Model analysis as needed, and then selected Tools Results command. On the Batch report dialog screen, enable the first option " Limit results to highlighted points ", from the online help: Use this option to limit the reported results to only points which are currently selected and thus highlighted on the screen. Note: see the online help for complete details on this command. Continue checking any additional feature on the dialog as necessary, and press the OK button. The output will display only those selected points in the respective sub-reports selected. 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!
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Wiki Page: Stress Summary output report subsection in AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Results Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers: Item #1: AutoPipe calculates the thermal range ratchet for that attached model as(9.48) for nodes 20,21,30 etc Doing the hand calculation for the thermal range ratchet the number is 193.48 see attached calculation. Would you please let me know why there is such difference? Answer: Readers of this wiki article should be warned that the following answer to the above question is per a specific model and set of Stress Summary settings and may not apply to your situation. 1. User is trying to confirm results for T19 and T20 only. However, in his stress summary he has quite a number of load pairs defined. This will result in the stress summary only displaying the worst case scenario i.e. one resulting in maximum stress ratio. 2. In the calculations the user sent, he is using psig instead of psi as defined in AutoPIPE model. therefore, the calculated value x is wrong. 3. The results given out by Stress Ratchet are using the minimum Sy value. The code requires to use average value for Syt from the two transients. However, the CAE development team has decided to use the minimum instead. This is conservative in nature. Workaround, adjust the had calculations accordingly to consider the min value to match output results. 4. The program can provide the results for T19 and T20 only by removing all load pairs in stress summary 2. This will show the ratchet results (using the minimum yield from T19 and T20) in the output report. 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!
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Wiki Page: AutoPIPE Compressor Vibration Method
Applies To Product(s): AutoPIPE Version(s): all Environment: N/a Area: Dynamic Subarea: N/A Original Author: Mark Upston, Bentley Technical Support Group Overview An out-of-balance compressor is inducing an oscillating vibration in the attached piping system. This causes concern with the forces, which are produced at the compressor nozzle, and pipe deflections near the compressor. Therefore, it is desired to model the harmonic loads in order to quantify the impact of the vibration on the system. Typically, the pipe/compressor connection point is instrumented, resulting in measurements of the amplitude of motion (A m ) and frequency of vibration (f m ). In order to accurately solve for piping displacements and the forces exerted on the compressor, it is necessary to determine the harmonic forces, which are induced at the compressor. Then, a harmonic analysis can be performed which produces the desired displacement and pipe force results. Harmonic Loads Modeling and Analysis Techniques NOTE : If there is more than one harmonic vibration source, at other points in the piping system, Steps 1-8 must be applied at each source independently in order to calculate all harmonic forces to be defined in a harmonic load case (HI - H3). However, once the stiffness values have been adjusted at an anchor they do not need to be temporarily set to "rigid" while the other sources are evaluated 1. At the anchor, which has been defined to represent the compressor, modify the translational stiffnesses by replacing "rigid" with "0" (zero) for each global coordinate direction, which is a component of Δ m . For example, if Δ m is observed to act along global X only, then only the "X" DOF is set to zero. However, if Δ m is observed to act in a skewed, 3D direction the "X", "Y", and "Z" DOF's should be zeroed. 2. Apply a unit "concentrated force" (f A ) at the anchored point for each released DOF. For example, if only the "X" DOF was set to zero, apply the force in the global X direction (f AX ). If all three DOF's were zeroed, apply forces in each global direction (f AX , f AY , and f AZ ). The applied forces should be placed into separate, isolated load cases (such as f AX - U1, f AY - U2, and f AZ - U3; where no other load effects are considered in Ul - U3). NOTE : Any applied force value can be used for the unit force since its magnitude scales the corresponding displacement calculated by AutoPIPE. However, care should be taken when considering the magnitude of the resulting displacement value because of the significant figures limitations in AutoPIPE reports. 3. Perform a static linear analysis in order to determine the translational displacements (Δ AX , Δ AY , and Δ AZ ) at the anchored point. NOTE : The applied force magnitude (f A ) can influence a nonlinear analysis result set (lift-off and gap closure), and AutoPIPE is only capable of linear supports in a dynamic analysis. 4. Calculate the stiffnesses (k) of the anchor for each released DOF as follows: K = ƒ A / Δ A · 10 3 this will result in a corresponding k X , k Y , and k Z value. The value "10E3" is somewhat arbitrary, but it is a reasonable assumption based on the stiffness of a "rigid" anchor DOF. Then change the anchor stiffnesses, which were set to zero in Step 1, to the values calculated in this step. 5. Calculate the (piping system) mass of the anchor point (manc). This is done by summing the weights of any components defined at the anchor point (i.e. flange, or weight) and the weight of the pipe (and contents) based on the half length to the next point (piping, soil, or mass). If the length of pipe between the anchored point and the next adjacent piping point is buried or if "automatic mass discretization" has been employed, the MODEL "list" report must be consulted to determine the number of "transparent" points added by AutoPIPE in order to calculate the correct half length. Once this total weight has been summed, divide by "g" (using appropriate units) to obtain the mass. 6. Calculate the cut-off frequency (f c ) to be specified for the modal analysis from the following equation: f c = √(K max /m anc ) where K max is the maximum of k X , k Y , and k Z calculated in Step 4. 7. Perform a modal analysis and specify the cut-off frequency calculated in Step 6. Make sure that the last mode calculated by AutoPIPE reaches the cut-off frequency. If it does not, rerun the modal analysis with a greater number of modes specified (along with the calculated f c ). Iterate until the last mode reaches f c . NOTE : This requirement can result in a large number of modes being captured. Missing mass and ZPA corrections do not impact the requirement of capturing the appropriate number of modes. 8. The harmonic force (F H ) loads are calculated from the following equation: F H = k · Δ m where "k" corresponds to the appropriate global direction, (k x , k v , and k z ). Thus, there may be F HX , F HY , and F HZ (these are the values entered in the HARMONIC LOAD form). The frequency value associated with these forces is the measured frequency (f m ). 9. Now, move on to the next (vibration source) anchor and repeat Steps 1 - 8 in order to calculate the harmonic forces (FH) to be applied at this location. NOTE : Step 9 can be ignored for a single vibration source and 0 phase angle used. Where multiple vibration sources exist in a piping system, each set of harmonic forces can be applied as an individual load case (one-to-one correspondence of source and load case), or they may be grouped into a single load case. If the latter scenario is desired, the phase angle relationship can be evaluated. 10. Once all harmonic forces are modeled and defined as desired, perform a final Modal analysis where the cut-off frequency is the maximum calculated for all vibration sources. Then, perform the harmonic analysis. The desired results can be obtained from the "Displacement" and "Restraint" reports, created using the Result / Output report, for the appropriate load cases (Hi - H3) or combinations of load cases. If all relevant modes have been captured, the resultant anchor displacements should be within 2% of the measured amplitude Δ m ). Piping forces and displacements for the remainder of the system will also be correct. However, if fewer modes are extracted, the anchor displacements reported by AutoPIPE will be near zero and the corresponding forces will be incorrect. Piping forces and displacements for the remainder of the system will be close to the correct values. Using AutoPIPE V8i 09.04.xx.xx and higher: The procedure refereed to above is meant for earlier versions of AutoPIPE (09.03.xx.xx and Lower). AutoPIPE V8i 09.04.xx.xx. and higher have harmonic displacement and velocity option which should be used instead. Recommend the following suggestions when modeling with the newer version of AutoPIPE: If your nozzle has some flexibility, the imposed displacement will be that of the pump and because of the flexibility only part of that displacement is applied to the pipe side. Recommend using the ZPA option when using harmonic loads as this will give you better nozzle reactions. The cut-off frequency should be at least 1.5 times the highest harmonic load frequency. Select Tools Model options Edit "Mass points per span", to add intermediate mass points based on the cut-off frequency. See Also Product TechNotes and FAQs External Links Bentley Technical Support KnowledgeBase Bentley LEARN Server Comments or Corrections? Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!
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Wiki Page: Harmonic Analysis - AutoPIPE
Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Analysis Subarea: Original Author: Bentley Technical Support Group Comments Questions and Answers about Harmonic analysis in AutoPIPE Item #1: Fatigue analysis with AutoPIPE Harmonic analysis command : AutoPIPE does not have cyclic type of stress, therefore need to add a new code combination with H1 by itself for the RPM of the harmonic from a rotation compressor: Combination Name = H1 Description = Harmonic Load case #1 for RPM = xxx . Combination method = 1 Sum Category = Occasional, Case = H1. Now, change the default "Allowable Stress" setting from "Automatic" (typical 1.33 *Sa) to 6500 psi. In this case, because a compressor is high cycle fatigue, API-618 mentions using a value of 26000 psi peak to peak. Therefore, use half of that which is 13000 psi peak to peak or to consider some SIF values typically would suggest using 13000/2 = 6500 psi for the Stress allowable. Therefore, 26000/2 for peak to peak, /2 assuming a weld stress factor = 2, because the piping codes are typically based on SIF while fatigue values are typically based on stress concentration factors and there is a factor of 2 between SIF and stress concentration factors AutoPIPE nuclear has a full fatigue analysis engine, however AutoPIPE Standard and Advance does not. This shortfall will be fixed in a future version of the application by enhancement CAE-CR-3268: Add fatigue analysis for ASME piping codes. Item #2: AutoPIPE Compressor Vibration Method Item #3: How can I include pulsation forces from piston type pump to piping? Answer: (from Karim Rinawi) The best way is to simulate the acoustic model using Bentley PULS. It will calculate the shaking forces and can export these using harmonic HMF file. Otherwise you would need to assume some pipe harmonic forces at elbows. Sometimes you need to change the load frequency to match pipe resonance for worst scenario. 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!
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