Getting started ! Introduction PepS is an integrated package containing PIPESTRESS, the piping analysis core program, and Editpipe, its pre- and post-processor. Are you using PepS for the very first time? Please read this tutorial carefully. It will explain what PIPESTRESS is, how it works and how Editpipe can help you exploit all its powerful features. You will also learn how to create your first piping model in less than 5 minutes, launch the calculation and view the results.
PIPESTRESS Overview What is PIPESTRESS PIPESTRESS is a program for performing linear elastic analysis of three-dimensional piping systems subject to a variety of loading conditions. Simple non-linearities in one-dimensional supports can be modelled. Chemical process piping, nuclear and conventional power generation piping systems may be investigated for compliance with piping codes and with other constraints on system response. What distinguishes PIPESTRESS from competitors is its advanced analysis capabilities and its rigorous QA methodology which has made it a reference in the nuclear piping industry: • • • • • • • • • • • • • • • • • • • • • • •
Full feature nuclear piping analysis program ASME Classes 1,2 and 3 and ANSI/ASME B31.1 ASME B31.3, CODETI RCC-M, KTA Classes 1 and 2 Code versions from 1967 to present Nuclear QA per 10CFR50, App. B, and 10CFR21 Heat transfer and thermal gradient stress Fatigue analysis usage factor Translators from other analysis programs Up to 500 user-defined load and combination cases Structures with 3,000 elements or more Element dimensions in Cartesian, cylindrical, spherical or sloping coordinates Thermal stratification Mixed class Composite materials Response cases with up to 99 independent support levels Response spectra in Cartesian or cylindrical coordinates Modal superposition by grouping, double sum CQC and other methods Time history analysis by generalized response method Selective “true” time history analysis Determination of rigid cut-off frequency for time history analysis Rigid mode correction for all dynamic analysis method Theory manual
The PIPESTRESS input file The standard input file for the PIPESTRESS program is an 80 character per-record text file, usually with a ‘fre’ extension, containing free format input and therefore called the ‘free’ file. Groups of records define the piping structure, loadings and other information required for the calculation. These groups of records are called "cards".
The PIPESTRESS result files PIPESTRESS generates a binary result file, the “restart” file, usually with a ‘rs1’ (or ‘rs2’, ‘rs3’, etc) extension, containing all computed displacement, forces and stresses. PIPESTRESS also generates reports in several text files which are identified by their extensions. If the PIPESTRESS input file is named follows. File name
filename.ext, then the reports are generated as
Reports Banners File information Echo Free format errors Modal extraction
Input data verification Formal input data description
Static load cases solutions
Floor response cases solutions
Time history cases solutions
Combination cases solutions
Fatigue analysis solutions Thermal transient solutions
Support summaries Contents Timing
Editpipe: the PIPESTRESS pre- and post-processor You could of course write the input PIPESTRESS file simply by means of a plain text editor such as Notepad, then launch PIPESTRESS in a DOS window by typing the PIPESTRESS command script and entering the input file name when prompted, and finally view the result files once again with Notepad… But what a waste of time! And you are never really sure whether the input file represents what you intended. Moreover, if there are errors in your input file, you discover them only after PIPESTRESS has terminated and you must then retrieve the error messages among the numerous text files generated by PIPESTRESS. This is where Editpipe comes into action! Here are some outstanding features of Editpipe:
• • • • • •
Advanced text editor environment with full syntax colouring for editing PIPESTRESS free format input files. The Easyfree templates assist you in creating or editing PIPESTRESS cards – in particular with the Smart Coordinate tool Instant visualization of the piping model defined in the input file, with input error detection Integrated database of PIPESTRESS free format input cards and standard piping fittings Post-processing module for visualizing mode shapes and load case displacements, forces and moments Tabular view of the data QuickPipe wizard helps you generate complete input files in less than 5 minutes Online help with an extensive description of the PIPESTRESS cards
Editpipe includes a powerful project and file manager, the Editpipe Manager, with the following features: • • • • • • • • •
Manage all PIPESTRESS input and output files related to a piping analysis project Run PIPESTRESS and related programs and follow progress of analysis Browse through output files with the PIPESTRESS report viewer Track errors reported during PIPESTRESS execution and point them out in the PIPESTRESS input file Extract the highest stress tables from your model, or stresses at chosen points View graphically binary input files like thf (time-history) files View support load sheets with special PPO file viewer Create Word-based stress reports from a user-defined template Review your actions with integrated logbook
Creating and analysing your first PIPESTRESS model: a short tutorial Let’s see how to apply these tools and create our first piping model!
1. Creating your first PIPESTRESS model with Quickpipe wizard With Quickpipe you are going to generate a complete PIPESTRESS input file for a simple piping model in less than 5 minutes, without even knowing anything about PIPESTRESS and its input card format. A simple model means that you have uniform piping cross section and operating conditions, and that the piping runs are following global axes. A sketch of the piping model to create is shown below: -
2” Shedule 10 pipe, A106 Gr B material Content: water One operating case: temperature=250°C, pressure=12 bar (1.2 N/mm²)
Editpipe 5.0 (c) 1996-2004 Tractebel
Launch the Editpipe Manager by double-clicking the PepS icon on the desktop screen. Click ‘Project Management : New Project’.
Select or create a directory where your project files will be stored.
Type the name of the PIPESTRESS input file to create: ‘demo.fre’
View Angles: (20.0,-26.7)
The Project Management Dialog prompts you for a general description of your project. You can skip and just press the OK button. An empty ‘demo.fre’ file has been created and is displayed in the ‘Text Input File’ box in the file explorer on the left.
Double-click ‘demo.fre’ or select ‘Edit/View Input File : Edit demo.fre’. You invoke the Editpipe editor. The ‘demo.fre’ file is empty and contains no cards yet.
Run the ‘Options : Quickpipe Wizard’ command.
The QuickPipe Wizard shows you 5 panels you have to fill in sequentially.
Fill in the ‘Plant’, ‘Title’ and ‘Engineer’ texts to identify your analysis. Choose the piping code and code version. The units are those selected in the Option menu. Choose the vertical axis (Y or Z)
Load Case data
Choose the number of thermal load cases. Add temperature and pressure. You could define an Earthquake case. Choose Quasi-static or R.G. 1.60 response spectrum.
Specify piping diameter, thickness and material, type of fluid and insulation weight.
Compose at the top of the screen a piping element (anchor, straight element, valve, restraint, lumped mass). Add the required direction, length and/or mass. Then press ‘Insert’ to insert the piping element in your lay-out. Press ‘Modify’ to change an existing element. It will be moved to the top of the panel. Apply the changes to the element, then press ‘Insert’ to insert the element back into the lay-out. Use ‘Cut’ and ‘Paste’ to duplicate elements.
Specify point numbering options. Define the bend radius (bends will be added automatically at each change of direction). Specify the end weld code (will be applied at each element). Then press “Create PIPESTRESS model”… and you are ready!
A complete input file has been created at lightning speed. The point labels have been generated automatically: 100 for the first point, incremented by 10 for the following points (110, 120 etc.). Two load cases have been generated: - CA=100: Weight - CA=101: Operating conditions A combination case “CA=401: Weight + Operating” has been created too. To get a graphical view of the model, just click the “Toggle View/Edit” button on the top toolbar. The buttons on this toolbar enable the user to invoke other useful commands: Go to Editpipe Manager Toggle View/Edit Easyfree tool
Print Save Open
Pan Rotate view Dynamic zoom Whole model
Increase/decrease symbol size Show supports Tabular data sheets Show point names
Don’t forget to save your model as ‘Demo.fre’ (command “File : Save”).
2. Launching the PIPESTRESS analysis Switch to the Editpipe Manager by clicking the ‘Editpipe Manager’ button.
Click ‘Run Analysis : Piping analysis’.
Simply press ‘OK’. The PIPESTRESS execution is displayed in the Execution Monitor window. When the execution finishes, Editpipe displays the Highest Stress file which summarizes the highest stress points for the different load cases. Close the Highest Stress file before proceeding.
3. Viewing the results The PIPESTRESS result files are listed in the ‘Result files’ box. To view any of the files, just double-click it. Editpipe allows you to visualize the results in a more graphical and convenient way. Return to Editpipe editor.
Click the command ‘Results : Load Restart File’ and select the restart file to load (in most cases the file is named ‘demo.rs1’).
Editpipe prompts you for the Load Case to view. Select for example: LOAD CASE 401: WEIGHT + THERMAL
A new toolbar has appeared on the top. Use its buttons to view the displacements, internal forces or stresses and to navigate through the different load cases: Force/moment component
Resultant moment Resultant force Display displacements
Choose load case
Display stresses Use local axis
View Highest stress table
Animate Size factor View tabulated results
It is generally more useful to view the stress ratios according to the piping code (ASME B31.1 in this case). A ratio higher than 1 means that stresses are over the limits permitted by the code. Click the command ‘Results : Load Highest stress table’. A table with the highest stresses for every load case is displayed and their locations are highlighted.
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4. Continuing to build the PIPESTRESS model The basic input file created with the Quickpipe wizard is a good starting point, but now you have to add other cards and a better understanding of the PIPESTRESS cards is required. Editpipe will be of great help once again. As already noted, the PIPESTRESS input file is a plain text file. Groups of records define the piping structure, loadings and other information required for the calculation. These groups of records are called "cards". The cards are identified by a four character card identity in the positions 1 to 4. For example, the first card of every PIPESTRESS input file is an "IDEN" card, the next card is a "TITL" card, etc. The order of the input is shown below: IDEN TITL Other Analysis cards
. Floor Response Spectrum cards (if required) Structure/Load cards
. ENDP Each card contains several fields that are entered in positions 6 to 80 in the following manner: ff=vvv... where ff is the field ident
vvv is the value to be entered Example: to define reference case number
320, enter RF=320
One card may extend in more than one line:
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CCAS CA=200 ME=8 EQ=1 C1=101 C2=102 TI=/THERM. + ANCHOR MOTION/ Comments lines are introduced with an asterisk: * This is a comment line The particular field ‘PT=…’ serves to define point identities. Point identities must be character strings consisting of one to four alphanumeric characters which are the digits 0,1,..,9, and the characters A,B,C,...,Z and a,b,c,...,z. For instance, the following line creates a straight pipe element whose length is 2.5 in X direction and whose end point identity is ‘60’: TANG PT=60 DX=2.5 Here are some of the most important PIPESTRESS cards: Analysis cards IDEN
Identification of the model. The piping code (ASME B31.1,…) and the units are defined therein
Titles and other options, in particular version of the piping code
Defines a Load Case for which PIPESTRESS will calculate displacements, rotations, forces, moments and stresses
Instructs PIPESTRESS to calculate "additive" stresses which are based on the resultant moments of the constituent cases
Structure/Load cards OPER
Defines the operating conditions for a load case for the members which follow this card until another OPER card for the same load case is encountered
Defines the size, weight and other section dependent properties of the pipe for members which follow this card until another Cross Sectional Properties card is encountered
Defines the material for members which follow this card until another MATL card is encountered
Defines a straight pipe element which is specified by a vector along the element axis
Defines a curved pipe element (bend or elbow) which is specified by its radius
Points of a piping system where all six displacement components are known (anchors)
Defines a single direction in which the piping system is restrained against displacement at the given point. A separate card must be used for each restraint direction
Indicates the end of the problem description. Cards which follow this card are ignored.
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You will find below a simple input file describing a 1” Sch.10 piping system, anchored at both ends, containing an elbow and subjected to a single operating case: temperature = 150°C, pressure = 10 bar: IDEN JB=1 CD=0 GR=-Y IU=0 OU=0 AB=T PL=/DEMO/ EN=/CAJ/ TITL BL=3 GL=1 CV=8 HS=1 TI=/EXAMPLE/ LCAS CA=100 TY=3 EQ=2 TI=/OPERATING WEIGHT/ LCAS CA=101 TY=0 EQ=7 TI=/THERMAL 1/ * MATERIAL: SA 106 Grade B (C-Si steel) *************************************** MATH CD=101 EX=1 TY=1 TX=371 MATD TE=21 EH=203.4 EX=10.08 SH=103.4 SM=137.9 MATD TE=93 EH=198.6 EX=10.96 SH=103.4 SM=137.9 MATD TE=149 EH=195.1 EX=11.57 SH=103.4 SM=137.9 MATD TE=204 EH=191.0 EX=12.13 SH=103.4 SM=137.9 MATD TE=260 EH=188.2 EX=12.71 SH=103.4 SM=130.3 MATD TE=316 EH=184.1 EX=13.10 SH=103.4 SM=119.3 MATD TE=371 EH=175.8 EX=13.52 SH=98.6 SM=115.8 MATL CD=101
SY=241.3 SY=219.9 SY=213.7 SY=206.8 SY=195.1 SY=178.6 SY=173.7
DESN TE=150 PR=1 PRES CA=100 PR=1 OPER CA=101 TE=150 PR=1 CROS ANCH TANG BRAD TANG
OD=33.40 WT=2.77 SO=1 ST=1 IN=0 MA=2.09 PT=100 PT=110 EW=2 DX=1 PT=120 EW=2 RA=0.0381 PT=130 EW=2 DZ=1
*1" Sch 10 10S *
5. Adding a branch line to your model Let’s return to the basic model you have just created. Imagine that a branch line starts from point 170, runs 2 meters along direction X and ends at an anchor point (representing for instance a vessel nozzle). The branch line is supported at midspan by a spring hanger. The operating conditions for the branch line are slightly different: 220°C, 10 bar. Switch to Editpipe editor and go to the end of the file, just before the ENDP card. Type the following lines, either by hand (in case you are already an experienced user…) or by using the Easyfree tool which lists and describes briefly the available cards and helps the user to define the fields. For examples, the next screen shows you how to create a CROS card defining an 8” Schedule 80 pipe cross section. Note the special field (*WT_OD): by doubleclicking this field, you access an integrated database of standard pipe sections.
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* By-pass line 1” comment line JUNC PT=170 the new branch starts from point 170 CROS OD=33.40 WT=2.77 MA=2.09 the branch is a 1" Sch 10 pipe: outside diameter = 33.4 mm (OD=33.4), thickness=2.77 mm (WT=2.77), linear weight=2.09 kg/m (MA=2.09) OPER CA=101 TE=120 PR=0.3 operating condition for load case 101: temperature = 120°C (TE=120), pressure = 0.3 N/mm² (PR=0.3) BRAN PT=300 TE=1 DX=0.0508 the tee is a welding tee (TE=1), the tee branch is 0.0508 m long in X direction (DX=0.0508) and the end point name is 300 (PT=300) TANG PT=310 DX=0.9492 the next pipe element goes from the end of the tee to mid-span at point 310 VSUP PT=310 DY=1. SP=1 FO=0.5 vertical spring hanger (DY=1) at point 310 (PT=310), spring stiffness=1 kN/mm (SP=1), pre-tension force = 0.5 kN (FO=0.5)
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TANG PT=320 DX=1 pipe element from point 310 to point 320 ANCH PT=320 anchor at point 320 View the model. You should get the following picture:
It’s that simple! Now, continue discovering the latest versions of PIPESTRESS and Editpipe integrated in the PepS package and enjoy unmatched technical excellence. Feel free to contact us for assistance or for additional information at [email protected]
or visit our website at www.dst.ch .