Course in FEM – ANSYS Classic - Aalborg...

Computational Mechanics, AAU, EsbjergFEM – ANSYS Classic

Course inFEM – ANSYS Classic

ANSYS Basics

ANSYS Basics 2Computational Mechanics, AAU, EsbjergFEM – ANSYS Classic

Basics• Launching of ANSYS• Graphical User Interface (GUI)• Menus, dialogs and toolbars• Working area• Preferences• Files used by ANSYS• ANSYS Menus• ANSYS File menu• ANSYS PlotCtrls menu• Units• Undo• Hints


Launching of ANSYS

Click on the Start menu at the bottom left corner of the screen.

Start ->Programs -> ANSYS Release 7.1 -> ANSYS Classic

..ANSYS Commands referenceANSYS Element reference..Basic Analysis ProceduresAdvanced Analysis Techniques..Structural Analysis Guide..ANSYS Tutorials


Launching of ANSYS• A note on Interactive vs. Batch mode:

– Interactive mode allows you to interact “live” with ANSYS, reviewing each operation as you go.

– Batch mode works on an input file of commands and allows you to run ANSYS in the background.

• No live interaction, therefore any errors in input will cause the batch run to stop.

• Best suited for operations that don’t need user interaction, such as a solve.

• Interactive mode is used in this course.


Launching of ANSYS

Set memory to 64 for total and 32 for database.

Set the default directory to be a directory on your disk where you want to save your ANSYSdatabase file.

Click on Run.

Jobname – specifies the name of allfiles in a session. The default is “file”or “FILE”.


Launching of ANSYSYou can include commands to be executed when the program starts up in the start71.ans file.


Graphical User Interface (GUI)Input

Displays program prompt messages and a text field for typing commands. All previously typed commands appear for easy reference and access.

Main MenuContains the primary ANSYS functions, organized by processors (preprocessor, solution, general postprocessor, etc.)

OutputDisplays text output from the program. It is usually positioned behind the other windows and can be raised to the front when necessary.


Graphical User Interface (GUI)Utility Menu

Contains functions which are available throughout the ANSYS session, such as file controls, selecting, graphics controls, parameters, and exiting.

ToolbarContains push buttons for executing commonly used ANSYS commands and functions. Customized buttons can be created.

GraphicsDisplays graphics created in ANSYS or imported into ANSYS.


Graphical User Interface (GUI)Main Menu• Contains the main functions required for an analysis.Utility Menu• Contains utilities that are generally available throughout the ANSYS session:

graphics, on-line help, select logic, file controls, etc.Input Window• Allows you to enter commands. (Most GUI functions actually “send” commands to

ANSYS. If you know these commands, you can type them in the Input Window.)• Also used for prompts during graphical picking.Toolbar• Contains abbreviations -- short-cuts to commonly used commands and

functions.• A few predefined abbreviations are available, but you can add your own.

Requires knowledge of ANSYS commands.• A powerful feature which you can use to create your own “button menu”

system!


Graphical User Interface (GUI)• The default view for a model is the front view:

looking down the +Z axis of the model.• To change it, use dynamic mode — a way to

orient the plot dynamically using the Control key and mouse buttons.– Ctrl + Left mouse button pans the model.– Ctrl + Middle mouse button:

zooms the model⌦spins the model (about screen Z)

– Ctrl + Right mouse button rotates the model:about screen X

⌦about screen Y

P Z R

Ctrl


Graphical User Interface (GUI)Mouse button assignments for picking:

• Left mouse button picks (or unpicks) the entity or location closest to the mouse pointer. Pressing and dragging allows you to “preview” the item being picked (or unpicked).

• Middle mouse button does an Apply. Saves the time required to move the mouse over to the Picker and press the Apply button. Use Shift-Right button on a two-button mouse.

• Right mouse button toggles between pick and unpick mode.

Pick

Apply

TogglePick / Unpick


Menus, dialogs and toolbars


Menus, dialogs and toolbarsSome dialog boxes have both Apply and OK

buttons.– Apply applies the dialog settings, but retains (does

not close) the dialog box for repeated use.– OK applies the dialog settings and closes the dialog

box.• The Output Window is independent of the

ANSYS menus. CautionCaution: Closing the output window closes the entire ANSYS session!

• Remember that you are not restricted to using the menus. If you know the command, feel free to enter it in the Input Window!


Working area


Preferences


PreferencesPreferences• The Preferences dialog (Main Menu > Preferences)

allows you to filter out menu choices that are not applicable to the current analysis.

• For example, if you are doing a thermal analysis, you can choose to filter out other disciplines, thereby reducing the number of menu items available in the GUI:– Only thermal element types will be shown in the element type

selection dialog.– Only thermal loads will be shown.– Etc.


Files used by ANSYS• *.db and *.dbb• *.log• *.rst• *.esav• *.emat• *.mode• *.full• *.mntr• *.osav• *.rdb• *.ldhi• *.err• *.avi

The jobname is a name that identifies the ANSYS job. When you define a jobname for an analysis, the jobname becomes the first part of the name of all files the analysis creates. (The extension or suffix for these files' names is a file identifier such as .DB.) By using a jobname for each analysis, you insure that no files are overwritten.

For a static or transient structural analysis, the file Jobname.RDB (a copy of the database) will be automatically saved at the first substep of the first load step.

The element matrix file


Files used by ANSYS• *.db and *.dbb• *.log• *.rst• *.esav• *.emat• *.mode• *.full• *.mntr• *.osav• *.rdb• *.ldhi• *.err• *.avi

The Jobname.LOG file (also called the session log) is especially important, because it provides a complete log of your ANSYS session.

File>Write DB log fileLGWRITE, Fname, Ext, --, Kedit


Files used by ANSYSFile Type File Name File Format

Log file Jobname.LOG ASCII

Error file Jobname.ERR ASCII

Output file Jobname.OUT ASCII

Database file Jobname.DB Binary

Results file: Jobname.xxx

structural or coupled Jobname.RST

thermal Jobname.RTH

magnetic Jobname.RMG

FLOTRAN Jobname.RFL

Load step file Jobname.Sn ASCII

Graphics file Jobname.GRPH ASCII (special format)

Element matrices Jobname.EMAT Binary

Binary


ANSYS Menus - File Menu

ANSYS Utility Menu


ANSYS Menus - Select Menu


ANSYS Menus - List Menu


ANSYS Menus - Plot Menu


ANSYS Menus - PlotCtrls Menu


ANSYS Menus - WorkPlane Menu


ANSYS Menus - Parameters Menu


ANSYS Menus - Macro Menu


ANSYS Menus - MenuCtrls Menu


ANSYS Menus - Help Menu


File menu

Clears (zeros out) the database stored in memory. Clearing the database has the same effect as leaving and reentering the ANSYS program, but does not require you to exit.

You can include commands to be executed when the program starts up in the start81.ans file.


File menu

You can change the default jobname using/FILNAMEor

Files opened before this command will onlychange name if set to “Yes”


File menu


File menu

Defines a title for the analysis. ANSYS includes the title on all graphics displays and on the solution output.


File menu

Reads the file Jobname.DB

You can save or resume the database from anywhere in the ANSYS program

Using the save and resume operations together is useful when you want to "test" a function or command.


File menuAllows you to restore a *.db or *.dbbwith an other file name than Jobname.db


File menu

The ANSYS program stores all input data (model dimensions, material properties, load data, etc.) and results data (displacements, stresses, temperatures, etc.) in one large database.


File menu

• The term ANSYS database refers to the data ANSYS maintains in memory as you build, solve, and postprocess your model.

• The database stores both your input data and ANSYS results data:– Input data - information you must enter, such as

model dimensions, material properties, and load data.– Results data - quantities that ANSYS calculates, such

as displacements, stresses, strains, and reaction forces.


File menu

Save and Resume• Since the database is stored in the computer’s

memory (RAM), it is good practice to save it to disk frequently so that you can restore the information in the event of a computer crash or power failure.

• The SAVE operation copies the database from memory to a file called the database file (or db file for short).


File menuTo specify a different file name

Any save operation first writes a backup of the current database file (if the database already exists) to Jobname.DBB. If a Jobname.DBB file already exists, the new backup file overwrites it.


File menu

• Notes on SAVE and RESUME:– Choosing the Save as or Resume from

function does NOT change the current jobname.

– If you save to the default file name and a jobname.db already exists, ANSYS will first copy the “old” file to jobname.dbb as a back-up.

– The db file is simply a “snapshot” of what is in memory at the time the save is done.


File menu


File menu

By default, the program saves the model and loads portions of the database automatically and writes them to the database file, Jobname.DB. If a backup of the current database file already exists, ANSYS writes it to Jobname.DBB.


PlotCtrls Menu


PlotCtrls Menu – View Settings


PlotCtrls Menu


Units• The ANSYS program does not assume a system

of units for your analysis. Except in magnetic field analyses, you can use any system of units so long as you make sure that you use that system for all the data you enter. (Units must be consistent for all input data.)

• Using the /UNITS command, you can set a marker in the ANSYS database indicating the system of units that you are using. This command does not convert data from one system of units to another; it simply serves as a record for subsequent reviews of the analysis.


Undo

• The UNDO command brings up the session editor, a text window that displays all of the program operations since the last SAVE or RESUME command. You can modify command parameters, delete whole sections of text and even save a portion of the command string to a separate file. The file is named jobname000.cmds, with each subsequent save operation incrementing the filename by one digit.

Main Menu>Preprocessor>Session Editor


Hints• Get familiar with

• This file can be easily edited in for example “Notepad”• For every “create/add” facility there is a “delete” function

in ANSYS• It may save time to build the model in ANSYS (and yield

better results) rather than importing from a CAD system• Use the “Alt-Tab” key to activate hidden dialog boxes or

activate the ANSYS output window if ANSYS stalls!!

File>Write DB log file LGWRITE, Fname, Ext, --, Keditor command key


Hints

• Tips on SAVE and RESUME:– Periodically save the database as you progress

through an analysis. ANSYS does NOT do automatic saves.

– You should definitely SAVE the database before attempting an unfamiliar operation (such as a Boolean or meshing) or an operation that may cause major changes (such as a delete).

• RESUME can then be used as an “undo” if you don’t like the results of that operation.

– SAVE is also recommended before doing a solve.


HintsFile Management Tips• Run each analysis project in a separate working

directory.• Use different jobnames to differentiate various analysis

runs.• You should keep the following files after any ANSYS

analysis:– log file ( .log), database file ( .db), results files, load step files, if

any (.s01, .s02, ...), physics files (.ph1, .ph2, ...).• Use /DELETE or Utility Menu > File > ANSYS File

Options to automatically delete files no longer needed by ANSYS during that session.

Course in FEM – ANSYS Classic - Aalborg...

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