Mech-UCO_120_WS-03_pipe

Workshop 3Workshop 3

Performing a Creep Analysis Using CommandAnalysis Using Command Objects

ANSYS Mechanical Advanced (Using Command Objects)

WS3-1ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved.

June 2009Inventory #002669

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Workshop 3

Training ManualIntroduction• An analysis of a half-symmetric of a pipe junction will be performed

in Mechanical APDL. Creep material properties are present, and the onset of buckling is examined



Workshop 3

Training ManualWorkshop Objectives• In this workshop, the following will be covered:– Defining additional material properties in Mechanical APDL– Examining the element coordinate systems– Using the Mechanical APDL log file– Using the General Postprocessor– Using the Time-History Postprocessor

• Informative text in this workshop is preceded by bullet point whereas steps to perform are designated with numberssteps to perform are designated with numbers.– This applies to top-level bullet/numbered items only

• APDL commands that can be typed in the Command Prompt areshown with T pe riter (Co rier) font



shown with Typewriter (Courier) font.

Workshop 3

Training Manual… Review Model Setup in Mechanical1. Launch ANSYS Workbench 12.0

• Windows Start menu > Programs > ANSYS 12.0 > Workbench2. Restore archive “workshop 3a.zip”p p

• “File menu > Restore Archive…”• Select “workshop 3a.zip” from the location specified by your instructor• Save the “pipe” project to a directory specified by your instructorp p p j y p y y



Workshop 3

Training Manual… Review Model Setup in Mechanical3. To open the Mechanical model, double-click on the “Setup” cell of

the “Creep Analysis for Workshop” system (labeled “B”):



Workshop 3

Training Manual… Review Model Setup in Mechanical4. Change the unit system using “Units menu > Metric (mm, kg, N…)”5. Review the model – note that a single surface body is present.

Right-click on the “Mesh” branch and use “Generate Mesh” to see the mesh. Check the loads and supports on this model.



Workshop 3

Training Manual… Review Model Setup in Mechanical• In the next steps, the following will be performed in Mechanical

APDL:– Specifying creep material properties– Solving the model– Postprocessing creep results



Workshop 3

Training Manual… Open the Model in Mechanical APDL1. Return to the Workbench Project Schematic2. Right-click on cell B5 (“Setup” cell of “Creep Analysis for

Workshop” system) and select “Update”3. Right-click on cell B5 and select “Transfer Data To New >

Mechanical APDL”



Workshop 3

Training Manual… Open the Model in Mechanical APDL4. Right-click on the cell C5 (“Analysis” cell of “Mechanical APDL”

system) and select “Edit in Mechanical APDL …”– The Mechanical APDL GUI will open with the model

5. Use “Utility Menu > Plot > Elements” to plot the mesh



Workshop 3

Training Manual… Verify Element Type6. Use “Main Menu > Preprocessor > Element Type > Add/Edit/Delete”

to list defined element types.• Click on [Close] when done

The pipe structure is represented with four-node quad shellnode quad shell elements (SHELL181).

The internal pressure loading is applied g ppusing surface effect elements (SURF154).



Workshop 3

Training Manual… Review Shell Sections7. Review the section properties for the shell elements by selecting

“Main Menu > Preprocessor > Sections > Shell > Lay-up > Add/Edit”• The Shell Sections dialog box will appear, as shown below.• Click on [OK] to close the dialog box when done



Workshop 3

Training Manual… Review Shell Sections• Some comments on shell sections:

• Note that multiple layers can be added with the [Add Layer] button for composite shells. Each layer can have a different material property ID

b ll diff t i l i t ti lnumber as well as different in-plane orientation angle.• For nonlinear materials, better accuracy can be obtained by increasing

the number of integration points through the thickness (shown on the previous slide is 3 integration points) For this analysis 3 integrationprevious slide is 3 integration points). For this analysis, 3 integration points has been specified, although, in general, 5 integration points is preferred when creep or plasticity is present. (As will be seen later, Mechanical APDL will automatically set this to 5 integration points to ensure better accuracy for creep calculations.)

• Shell offsets, if specified in Mechanical, will also appear in the Shell Sections dialog box shown on the previous slide.Th “S ti F ti ” f t i t d fi th h ll thi k• The “Section Function” feature is a way to define the shell thickness as a function of position.

• Additional details on shells can be found in the Help system:• “Mechanical APDL (formerly ANSYS) > Structural Analysis Guide > Ch 17 Shell



Mechanical APDL (formerly ANSYS) > Structural Analysis Guide > Ch. 17 Shell Analysis and Cross Sections”

Workshop 3

Training Manual… Show Element Coordinate Systems8. Select “Utility Menu > PlotCtrls > Symbols …”– Select “ESYS Element coordinate sys” to “On” (when checked, the

current value of “On” will be shown)9. Turn on wireframe mode via “Utility Menu > PlotCtrls > Device

Options …”– Select “[/DEVI] Vector mode (wireframe)” to “On”



Workshop 3

Training Manual… Show Element Coordinate Systems• The element coordinate system and boundary conditions will be

displayed in wireframe (vector) mode.• Zoom in/out; right-click on the Graphics window and use “Replot” to

refresh the screen.• Note that element element has the z-axis (blue) pointed inward. The

x-axis (black/white) and y-axis (green-blue) are “random,” however.

The default element coordinate system for SHELL181 is actual ynot “random” but based on node I-J and L-K orientation, as described in the Element Reference help manualReference help manual.

Using a local coordinate system, one could align the element coordinate systems if needed



coordinate systems, if needed.

Workshop 3

Training Manual… Hide Element Coordinate Systems10.Select “Utility Menu > PlotCtrls > Symbols …”– Select “ESYS Element coordinate sys” to “Off”– (Optional) If the boundary condition symbols are to also be hidden, at

the top of the dialog box, change “[/PBC] Boundary condition symbol” to the “None” radio button

11.Turn off wireframe mode via “Utility Menu > PlotCtrls > Device O ti ”Options …”– Select “[/DEVI] Vector mode (wireframe)” to “Off”



Workshop 3

Training Manual… Add Creep Material Property12.“Main Menu > Preprocessor > Material Props > Material Models”

• In the Material Models dialog box, expand the right column: “Structural > Nonlinear > Inelastic > Rate Dependent > Creep > Creep only > Mises P t ti l I li it 10 N t (S d )”Potential > Implicit > 10: Norton (Secondary)”



Workshop 3

Training Manual… Add Creep Material Property• The Norton law is a very simple creep law, as shown below:

TC

CC3

2

−

&

– εcr is equivalent creep strain (the dot denotes time derivative, or the creep

TCcr eC 2

1= σεc

strain rate)– σ is the equivalent stress– T is the absolute temperature

• To allow users to specify temperatures in Celsius or Fahrenheit, the TOFFSTcommand is used to specify the offset that is used for the creep equation

– C1 through C3 are the material constants input by the userFor details on available creep laws see the following Help section:– For details on available creep laws, see the following Help section:

• “Mechanical APDL (formerly ANSYS) > Element Reference > 2.5 Material Data Tables (Implicit Analysis) > 2.5.13.1 Implicit Creep Equations”

– For this example, no temperature effects are considered, so C3=0. C1 is



o t s e a p e, o te pe atu e e ects a e co s de ed, so C3 0 C s9.18e-13 and C2 is 5.54

Workshop 3

Training Manual… Add Creep Material Property13. In the Creep dialog box, enter the constants as shown below:

• C1 is 9.18e-13• C2 is 5.54• C3 is 0 (no temperature effects for this example)• Click on [OK] when done. Notice that “Creep: Implicit (10: Norton-S)”

will be added under “Material Model Number 1” on the left side of the M i l M d l GUI U “M i l E i ” l h GUIMaterial Models GUI. Use “Material menu > Exit” to close the GUI.



Workshop 3

Training Manual… Reviewing Log File• The log file records all actions that were performed by the user.14.“Utility menu > List > Files > Log File …”

• Scroll to the bottom of the text window that appears. The commands to ppdefine the creep model are shown in the listing.



Workshop 3

Training Manual… Reviewing Log File• Understanding which APDL commands correspond to the actions the

user performs can be difficult for those unfamiliar with APDL.• A helpful tip is to ‘annotate’ the log file:– A comment can be inserted in the log file by preceding it with an

exclamation mark “!”– Comments and commands can be typed in the Command Prompt

– By taking advantage of comments, one can type a comment in the Command Prompt prior to performing an action in the GUI. Then, after th ti i l t d t i th t ill th t t ththe action is completed, typing another comment will then annotate the log file.

– An example will be performed in the next steps.



Workshop 3

Training Manual… Setting Solution Options1. In the Command Prompt, type “! Start of changing solution

options” (do not include the double quotes) and hit the Enter key

2 Select “Main Menu > Solution > Analysis Type > Sol’n Controls”2. Select Main Menu > Solution > Analysis Type > Sol n Controls– A warning will appear indicating current solution options are not

supported. Click on [OK].– The Solution Controls dialogThe Solution Controls dialog

box will appear, as shown onthe right



Workshop 3

Training Manual… Setting Solution Options• Since Mechanical does not support creep material input, it does not

request saving the creep strain output. In the next steps, all results (including creep strain) will be saved every 3 timesteps

3. On the left side, ensure that “All solution items” is selected. Change “Frequency” to “Write every Nth substep”, then enter “3” in the text area. Click on [OK] when done.



Workshop 3

Training Manual… Setting Solution Options4. In the Command Prompt, type “! End of changing solution

options” and hit the Enter key

5. “Utility menu > List > Files > Log File …”– Notice that the comments entered earlier separate the commands used

to save all results every 3 timesteps This allows users unfamiliar withto save all results every 3 timesteps. This allows users unfamiliar with APDL to isolate required commands to perform specific tasks



Workshop 3

Training Manual… Solve First Step6. “Main Menu > Solution > Solve > Current LS”

• A text window giving a summary of the solution options will be shown. Notice that “Load Step Number” is 1 (first Step), and the simulation

di ti i 1 6 Cl th t t i d th li k [OK] t lending time is 1e-6. Close the text window, then click on [OK] to solve.



Workshop 3

Training Manual… Solve First Step• Two warning messages will appear. One can bring up the Output

Window to see the messages in detail.

– One warning is related to element shape checking not being performed, but this can be ignored since shape testing has already been done in the meshing phase in Mechanical.Th th i t th t 3 i t ti i t th h th thi k– The other warning notes that 3 integration points through the thickness of shells may not give accurate results, so the number of integration points has been increased to 5.

7 Click on [Yes] to proceed



7. Click on [Yes] to proceed

Workshop 3

Training Manual… Solve First Step8. Another warning will appear. Click on [Yes] to initiate the solution.

• The second warning appears after Mechanical APDL does a material check. Reviewing the contents of the Output Window and looking for th l t f th d *** G *** ill h th t thithe last occurrence of the word *** WARNING *** will show that this warning message is related to some elements not having material properties associated with them. The surface effect elements that are present in the model are used to apply pressure loads – since they do p pp y p ynot represent a physical structure, they have no material properties, so this warning message can be safely ignored.

• After the solution completes, click on [Close] to close the notification dialog box, but do not click on anything else.



Workshop 3

Training Manual… Solve First Step• The previous step only solved the first step, and it should be a

relatively fast solution.• Creep analyses are time-dependent analyses. For this pipe model, an

internal pressure of 0.25 MPa is applied. The first step is used to establish initial conditions (e.g., stress). The simulation time is set very low (1e-6) so as not to influence the time-dependent creep ffeffects.

• Once this initial step is completed, we will now solve the analysis until time=28000 seconds for the second Step.– Mechanical APDL treats consecutive “solves” as continuation of steps.– If, on the other hand, the user clicks on “Preprocessor” or “General

Postproc” in the Main Menu, the user is ‘leaving’ the Solution processor. When a user returns to the Solution processor to solve a new analysisWhen a user returns to the Solution processor to solve, a new analysis will be assumed (solving Step 1) unless the user performs a restart.



Workshop 3

Training Manual… Solve Second Step1. “Main Menu > Solution > Analysis Type > Sol’n Controls”– In the “Time Control” section, specify “Time at end of loadstep” to be

“28000”– Set “Automatic time stepping” to “On”– With “Time increment” selected, enter “1e-6” for both “Time step size”

and “Minimum time step” while “Maximum time step” is “1000”(D l h di l b )– (Do not close the dialog box yet)



Workshop 3

Training Manual… Solve Second Step2. Select the “Nonlinear” tab in the Solution Controls dialog box.

Click on “Include strain rate effect” to turn creep effects on.3. Click on [OK] to close the Solution Controls dialog box



Workshop 3

Training Manual… Solve Second Step4. “Main Menu > Solution > Solve > Current LS”

• Review the text window with the solution summary. Note that the “Load Step Number” is now “2”. The ending time and timestep settings should b i t t ith h t i t libe consistent with what was input earlier.

• Close the text window, then click on [OK] to initiate the solution. A warning will appear (check the Output Window to see that this is related to material properties not being defined for some elements – thisto material properties not being defined for some elements – this warning can be safely ignored), and click on [Yes] to continue

• The solution may take 3-10 minutes, depending on the hardware used. While the solution is running, please read the next slides. (When the solution is completed, the [Close] button can be clicked to remove the notification dialog box.)



Workshop 3

Training Manual… Solve Second Step• The initial and minimum timestep is set to “1e-6” for this example to

be consistent with the first Step of 1e-6. The user can elect to use a bigger initial timestep. However, in creep problems, it is usually the initial timesteps where the creep strain rate is high – there is a term proportional to σC2 as shown earlier, and as creep strains develop, the stress relaxes. Hence, earlier time values may have greater significance so having an initial timestep that is small will capturesignificance, so having an initial timestep that is small will capture the change in creep strain rate more accurately.

• If a timestep of 1e-6 is used with an ending time of 28000, that would involve an extraordinary number of timesteps to completeinvolve an extraordinary number of timesteps to complete. Automatic time-stepping is turned on to allow Mechanical APDL to increase the timestep, as needed.

• Saving results every 3 timesteps had been specified earlier so this• Saving results every 3 timesteps had been specified earlier, so this setting will still be in effect.

• Creep effects are not turned on by default even if the material properties are defined so that will be done next



properties are defined, so that will be done next.

Workshop 3

Training Manual… Solve Second Step• During solution, the force and moment residuals from the Newton-

Raphson iterations will be plotted on the screen.– This is the same output as “Force Convergence” and “Moment

Convergence” in Mechanical, under the “Solution Information” branch• The solution takes over 300 iterations to solve– As will be seen shortly, this is a creep buckling problem. During the

solution, large creep strains are encountered near the end time, so smaller timesteps are required to accurately predict the deflections.



Workshop 3

Training Manual… General Postprocessor1. To review the results available, select “Main Menu > General

Postproc > Read Results > By Pick”• Note that there are 39 result sets available (every 3rd timestep was

saved). Select the last result set, click [Read], then [Close].



Workshop 3

Training Manual… General Postprocessor2. Plot creep strains via “Main Menu > General Postproc > Plot Results

> Contour Plot > Element Solu”– In the “Contour Element Solution Data” dialog box, select “Element

Solution > Creep Strain > von Mises creep strain” and click [OK]– Equivalent APDL command is PLESOL,EPCR,EQV



Workshop 3

Training Manual… General Postprocessor3. Because surface effect elements exist on top of shell elements,

only SHELL181 elements should be selected. Use “Utility Menu > Select > Entities …”, then fill out the widget as shown below.• Click on [Apply], then [Replot] to replot the creep strains• APDL Command is ESEL,S,ENAME,,181



Workshop 3

Training Manual… General Postprocessor• In Mechanical APDL, nodal solution represents averaged stress

results, along with nodal DOF results (e.g., displacements). On the other hand, element solution is unaveraged stress/strain results.– This is similar to the “Use Average” option in the Details view for contour

results in Mechanical•PLNSOL or PLESOL plot contour results. A helpful reminder of this

t i “PL t N d l/El t SOL ti ”syntax is “PLot Nodal/Element SOLution”.– The first argument is the type of result, and the second is the component– PLNSOL,S,EQV plots nodal solution of EQuiValent Stress (“S”=sigma)– PLESOL,EPCR,EQV plots element solution of EQuiValent CReep strain

(“EP”=epsilon).– See the Commands Reference for syntax on PLESOL and PLNSOL. PLVECT for vector plotting is also available and PRESOL/PRNSOL listPLVECT for vector plotting is also available, and PRESOL/PRNSOL list (PRint) the values.

– Chapter 7 “The General Postprocessor (POST1)” of the Basic Analysis Guide is also a good reference for postprocessing in Mechanical APDL



g p p g

Workshop 3

Training Manual… General Postprocessor4. In the Command Prompt, type “HELP,SHELL181”. The online help

for SHELL181 will appear. Scroll to the bottom to Table 181.2– Notice that the ‘average thickness’ has a name called “THICK”



Workshop 3

Training Manual… General Postprocessor5. Scroll down further to Table 181.3. Look for the occurrence of

“THICK”. It is indicated by “Item=SMISC” and “E=17”



Workshop 3

Training Manual… General Postprocessor• There are results which may be element-specific. For example, the

current “thickness” of an element would only be applicable for shell elements, not solid or beam elements. These element-specific output are stored in summable and non-summable miscellaneous data.(“NMISC” = non-summable miscellaneous data, “SMISC” = summable miscellaneous data)R i h El R f f i l l ( )• Review the Element Reference for a particular element type to (a) see what type of output is available and (b) determine how to retrieve that data, if the result is element-specific

I thi l T bl 181 2 h d h t ki d f t t d t– In this example, Table 181.2 showed what kinds of output data are available. The last column with a “Y” indicates this output is available in the results file for postprocessing

– Table 181 3 shows how to retrieve element-specific results The currentTable 181.3 shows how to retrieve element-specific results. The current, average thickness of the shell elements are output using “SMISC,17”



Workshop 3

Training Manual… General Postprocessor6. Plot shell thicknesses via “Main Menu > General Postproc > Plot

Results > Contour Plot > Element Solu”– In the “Contour Element Solution Data” dialog box, select “Element

Solution > Miscellaneous Items > Summable data (SMISC,1)”– When prompted, enter “17” for the sequenc number. Click on [OK] twice– Equivalent APDL command is PLESOL,SMISC,17



Workshop 3

Training Manual… General Postprocessor• The resulting plot of shell thickness is shown below. Note that the

initial thickness was 10 mm – thickness increases in some regions due to the negative applied pressure. With large deflection effects turned on, the change in thickness is calculated based on incompressibility considerations.



Workshop 3

Training Manual… General Postprocessor7. Plot z-displacement via “Main Menu > General Postproc > Plot

Results > Contour Plot > Nodal Solu”– In the “Contour Nodal Solution Data” dialog box, select “Nodal Solution

> DOF Solution > Z-Component of displacement”– Equivalent APDL command is PLNSOL,U,Z



Workshop 3

Training Manual… General Postprocessor8. To retrieve the minimum z-displacement as a parameter, use “Utility

menu > Parameters > Get Scalar Data…”– Select “Results Data” from the left column and “Global measures” from

the right area. Click on [OK] to continue– In the next dialog box, select “DOF solution” on the right, then “UZ” on

the left. Type “Min_Deflection” in the text area, and change the pull-down menu to “Minimum value” Click on [OK]down menu to Minimum value . Click on [OK]

– Equivalent APDL commands are NSORT,U,Z followed by *GET,Min_Deflection,SORT,,MIN



Workshop 3

Training Manual… General Postprocessor• Notice in the Output Window that the following is displayed:

• The previous step automatically retrieved the minimum z-deflection from the selected nodes and assigned the value to a parameterfrom the selected nodes and assigned the value to a parameter (variable) called “Min_Deflection”

• The usefulness of APDL parameters will be discussed later, but this is an introduction to the APDL *GET command which allows users tois an introduction to the APDL GET command, which allows users to retrieve information about the model or results automatically.



Workshop 3

Training Manual… General Postprocessor9. In the Command prompt, type the following:

*get,Min_UZ_Node,sort,,iminand hit the Enter key when done.

Look at the Output Window, and notice that the parameter “MIN_UZ_NODE” has been assigned a value of 1406. This means that node number 1406 has the minimum z-deflection reportedthat node number 1406 has the minimum z-deflection, reported earlier as -53.5.

• Note that if differences in the meshing algorithm may make the node



• Note that if differences in the meshing algorithm may make the node number ID and values different from above.

Workshop 3

Training Manual… Time-History Postprocessor• The plot of deflection at the node with the largest –z displacement

may be of interest.• In the next section, the z-deflection as a function of time will be

plotted in the Time-History Postprocessor



Workshop 3

Training Manual… Time-History Postprocessor1. Select “Main Menu > TimeHist Postproc”. The Time-History

Variable Viewer should appear, as shown below:



Workshop 3

Training Manual… Time-History Postprocessor2. Click on the “Add Data” icon in the Variable Viewer

3. Select “Nodal Solution > DOF Solution > Z-Component of displacement” and click on [OK]



Workshop 3

Training Manual… Time-History Postprocessor4. In the “Picker” dialog box, type “min_uz_node” in the text area. Be

sure to hit the Enter key. The node should then be highlighted on the screen.• Hint: If the Time History Variable Viewer is obstructing the view, click on

the “Variable List” and “Calculator” titles to collapse those sections.



Workshop 3

Training Manual… Time-History Postprocessor5. After the Enter key is pressed, the Picker should indicate 1 node

selected, and the Graphics window will show that node highlighted. Click on [OK] on the picker to continue.



Workshop 3

Training Manual… Time-History Postprocessor6. If the Variable List was collapsed, click on the title bar to expand it

again, as shown below. With the “UZ_2” item highlighted, click on the “Graph Data” icon to plot z-displacement as a function of time



Workshop 3

Training Manual… Time-History Postprocessor• The plot of deflection vs. time indicates that, as time increases past

24000 seconds, the deflection quickly increases dramatically, indicating geometric instability (creep buckling):



Workshop 3

Training Manual… Time-History Postprocessor7. Use “Utility menu > File > Exit …” to exit Mechanical APDL– You can save the database or exit without saving. The Mechanical APDL

data is no longer required for the rest of this exercise.



Workshop 3

Training Manual… Creep Analysis in Mechanical• Everything that was performed in Mechanical APDL can actually be

accomplished with the use of Commands objects. This will be discussed in the next section.



Workshop 3

Training Manual… Creep Analysis in Mechanical1. Return to the Workbench Project Schematic.2. Double-click on cell A7 – the “Results” cell of the “Creep Analysis,

Solved in Mechanical” system.



Workshop 3

Training Manual… Creep Analysis in Mechanical3. Expand the “Geometry > Surface Body” branches. Note the

Commands object named “Material Properties”• Look at the contents of the file. This defines the section properties

(optional) as well as adds the creep material properties (required)



Workshop 3

Training Manual… Creep Analysis in Mechanical• The steps manually performed earlier can be incorporated directly in

the Mechanical model.– APDL commands are case-insensitive. Also, APDL commands only

require the first 4 letters, as long as those first 4 letters are unique.– There is a term called “MATID” used in this Command object. This is a

parameter that substitutes the actual material ID for that part. Hence, if we have an assembly with many parts we do not have to know the actualwe have an assembly with many parts, we do not have to know the actual material ID for each part but just use the parameter “MATID” whenever an ID number input is required in an APDL command argument

– The parameters “ARG1” and “ARG2” are special. Note in the Details view p pthat a user can specify the value for ARG1 and ARG2. These values are then substituted wherever ARG1 and ARG2 are used in the Commands object.



Workshop 3

Training Manual… Creep Analysis in Mechanical4. Review the “Analysis Settings” branch– The specification of ending time and timesteps that were performed in

Mechanical APDL can also be done directly in Mechanical



Workshop 3

Training Manual… Creep Analysis in Mechanical5. Select the “Turn on Creep Effects from Step 2” branch– Earlier, creep effects were turned on in load step 2 in Mechanical APDL.

This is done with the RATE,ON command– The Details view shows that this command will only be active in Step 2



Workshop 3

Training Manual… Creep Analysis in Mechanical6. Select the “Save all (creep) results every 3 timesteps” branch– Refer back to earlier steps in this workshop – when the log file was

annotated with our comments, the same commands are used here to lt 3 ti t l i t i t dsave results every 3 timesteps, also ensuring creep strains are stored

(creep strains are not stored by Mechanical by default)



Workshop 3

Training Manual… Creep Analysis in Mechanical7. Review the results of the “Direction Deformation” branch. The

reported z-deflections should match the earlier results reviewed in Mechanical APDL.



Workshop 3

Training Manual… Creep Analysis in Mechanical8. Review the “Equivalent Creep Strain” branch.

• This is a user-defined result. Notice in the Details view that “Expression” is “EPCREQV”, the same notation used earlier in M h i l APDL ( ith t th ) U d lt hMechanical APDL (without the comma). Unaveraged results are shown and should match with results reviewed earlier in Mechanical APDL



Workshop 3

Training Manual… Creep Analysis in Mechanical9. Select the “Solution” branch. From the context toolbar, add “User

Defined Result”



Workshop 3

Training Manual… Creep Analysis in Mechanical10. In the Details view of the newly-added “User Defined Result”

branch, enter “SMISC17” for “Expression” and change “Use Average” to “No”. Right-click and “Evaluate Results” to see the

fthickness of shells, similar to what was done in Mechanical APDL:



Workshop 3

Training Manual… Creep Analysis in Mechanical• The use of parameters and APDL commands allows users to

incorporate additional, advanced features such as creep, to a Mechanical analysis.

• The use of “User Defined Results” in Mechanical also exposes many types of results that can be postprocessed directly in Mechanical

• However, it is very helpful to the user to understand how the process in Mechanical APDL works.– Understanding how Mechanical APDL references element attributes is

important to incorporating advanced material models or element options– Verification of the mesh, such as composite layer or element coordinate

system orientation, may need to be performed in Mechanical APDL– Postprocessing of esoteric results may not be available in Mechanical’s

“User Defined Results” and may need to be done in Mechanical APDL“User Defined Results” and may need to be done in Mechanical APDL.– Moreover, if elements were added in Mechanical APDL, the

postprocessing would need to be done in Mechanical APDL as well.



• This concludes the present workshop

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