ANSYS Command File Creation and Execution

Generating the Command File

There are two choices to generate the command file:

1. Directly type in the commands into a text file from scratch. This assumes a good knowledge of the ANSYS command language and the associated options.

If you know what some of the commands and are unsure of others, execute the desired operation from the GUI and then go to File -> List ->

Log File. This will then open up a new window showing the command line equivialent of all commands entered to this point. You may directly cut and paste from here to a text editor, or if you'd like to save the whole file, see the next item in this list.

2. Setup and solve the problem as you normally would using the ANSYS graphic user interface (GUI). Then before you are finished, enter the command File -> Save DB Log File This saves the equivalent ANSYS commands that you entered in the GUI mode, to a text file. You can now edit this file with a text editor to clean it up, delete errors from your GUI use and make changes as desired.

Running the Command File

To run the ANSYS command file,

• save the ASCII text commands in a text file; e.g. frame.cmd • start up either the GUI or text mode of ANSYS

GUI Command File Loading

To run this command file from the GUI, you would do the following:

• From the File menu, select Read Input from.... Change to the appropriate directory where the file (frame.cmd) is stored and select it.

• Now ANSYS will execute the commands from that file. The output window shows the progress of this procedure. Any errors and warnings will be listed in this window.

• When it is complete, you may not have a full view of your structure in the graphic window. You may need to select Plot -> Elements or Plot -> Lines or what have you.

• Assuming that the analysis worked properly, you can now use the post-processor to view element deflections, stress, etc.

• If you want to fix some errors or make some changes to the command file, make those changes in a separate window in a text editor. Save those changes to disk.

• To rerun the command file, you should first of all clear the current model from ANSYS. Select File -> Clear & Start New.

• Then read in the file as before File -> Read Input from...

Command Line File Loading

Alternatively, you can also read in the command file right from the ANSYS command line. Assuming that you started ANSYS using the commands... /ansys52/bin/ansysu52 and then entered /show,x11c This has now started ANSYS in the text mode and has told it what graphic device to use (in this case an X Windows, X11c, mode). At this point you could type in /menu,on, but you might not want to turn on the full graphic mode if working on a slow machine or if you are executing the program remotely. Let's assume that we don't turn the menu mode on... If the command file is in the current directory for ANSYS, then from the ANSYS input window, type /input,frame,cmd and yes that is a comma (,) between frame and cmd. If ANSYS can not find the file in the current directory, you may need to point it to the proper directory. If the file was in the directory, /myfiles/ansys/frame for example, you would use the following syntax /input,frame,cmd,/myfiles/ansys/frame If you want to rerun a new or modified file, it is necessary to clear the current model in memory with the command /clear,start This full procedure of loading in command files and clearing jobs and starting over again can be completed as many times as desired.

ANSYS Command Groupings

ANSYS contains hundreds of commands for generating geometry, applying loads and constraints, setting up different analysis types and post-processing. The following is

only a brief summary of some of the more common commands used for structural analysis.

Category Command Description Syntax

Basic Geometry k keypoint

definition k,kp#,xcoord,ycoord,zcoord

l straight line creation l,kp1,kp2

larc circular arc line (from keypoints)

larc,kp1,kp2,kp3,rad (kp3 defines plane)

circle circular line creation (creates keypoints)

see online help

spline spline line through keypoints

spline,kp1,kp2, ... kp6

a area definition from keypoints a,kp1,kp2, ... kp18

al area definition from lines a,l1,l2, ... l10

v volume definition from keypoints

v,kp1,kp2, ... kp8

va volume definition from areas

va,a1,a2, ... a10

vext create volume from area extrusion

see online help

vdrag create volume by dragging area along path

see online help

Solid Modeling (Primitives)

rectng rectangle creation rectng,x1,x2,y1,y2

block block volume creation block,x1,x2,y1,y2,z1,z2

cylind cylindrical volume creation cylind,rad1,rad2,z1,z2,theta1,theta2

sphere spherical volume creation sphere,rad1,rad2,theta1,theta2

prism cone torus

various volume creation commands

see online help

Boolean Operations aadd

adds separate areas to create single area

aadd,a1,a2, ... a9

aglue creates new areas by glueing (properties remain separate)

aglue,a1,a2, ... a9

asba creat new area by area substraction asba,a1,a2

aina create new area by area intersection

aina,a1,a2, ... a9

vadd vlgue vsbv vinv

volume boolean operations see online help

Elements & Meshing et defines element

type

et,number,type may define as many as required; current type is set by type

type set current element type pointer

type,number

r define real constants for elements

r,number,r1,r2, ... r6 may define as many as required; current type is set by real

real sets current real constant pointer real,number

mp sets material properties for elements

mp,label,number,c0,c1, ... c4 may define as many as required; current type is set by mat

mat sets current material property pointer

mat,number

esize sets size or number of divisions on lines

esize,size,ndivs use either size or ndivs

eshape controls element shape see online help

lmesh mesh line(s) lmesh,line1,line2,inc or lmesh,all

amesh mesh area(s) amesh,area1,area2,inc or amesh,all

vmesh mesh volume(s) vmesh,vol1,vol2,inc or vmesh,all

Sets & Selection ksel select a subset of

keypoints see online help

nsel select a subset of nodes see online help

lsel select a subjset of lines see online help

asel select a subset of areas see online help

nsla select nodes within selected area(s)

see online help

allsel select everythingi.e. reset selection

allsel

Constraints dk defines a DOF constraint on a keypoint

dk,kp#,label,value labels: UX,UY,UZ,ROTX,ROTY,ROTZ,ALL

d defines a DOF constraint on a node

d,node#,label,value labels: UX,UY,UZ,ROTX,ROTY,ROTZ,ALL

dl defines (anti)symmetry DOF constraints on a line

dl,line#,area#,label labels: SYMM (symmetry); ASYM (antisymmetry)

Loads fk defines a fk,kp#,label,value labels: FX,FY,FZ,MX,MY,MZ

f defines a force at a node

f,node#,label,value labels: FX,FY,FZ,MX,MY,MZ