Ansys Quick Reference

8/8/2019 Ansys Quick Reference

1/10

ANSYS Quick Reference Acknowledgements

www.come.tum.deTechnical University of Munich

This paper is to a great extent based on the work by Prof. Dr.-Ing. habil. Manfred Bischoff, Institute of Structural Mechanics,University of Stuttgart (http://www.ibb.uni-stuttgart.de), and Dipl.-Ing. Moritz Frenzel M.Sc., Chair of Computational Mechanics,Technical University of Munich (http://www.lnm.mw.tum.de). Wegratefully acknowledge their permission to use their work.

Introduction

This is not an ANSYS manual! ANSYS is a general purpose finite element package whose full documentation is availableas online help and would fill half a bookshelf when printed. There are numerous tutorials and sample problems available on

the internet, but all of them serve different, and mostly specific purposes, reflecting the numerous areas of applicability ofANSYS (structural, thermal, electrical, etc.).

This little quick reference collects hints to the most important features in the context of the courses Modeling and Simulation Iand II within the Master Program in Computational Mechanics at the TU Mnchen. It is intended to serve as a help to getstarted with ANSYS. After getting familiar with these basic steps it should be no problem to handle more complexapplications with the help of the aforementioned online manual.

Disclaimer: We do not take any responsibility for the information herein. This quick reference is not licensed, sponsored orconnected in any other way to ANSYS. If you downloaded this document and you are not a student of CoMe.TUM, pleasedrop us a note ([email protected]).


2/10

General Procedure

ANSYS provides two principally different methods to issue commands: Either using a menu structure or a command line.Professionals who use ANSYS usually work with the command line because it is more efficient and provides an easypossibility to use readily prepared macros (often used command sequences).

To get started, however, it is recommended to use the menus. They help to lo lead you through the process of model creation,meshing, solving and plotting the results and provide a quick overview of the possibilities that the program offers. Note:depending on the ANSYS version, the menues might differ slightly from the examples herein.

The main steps of a typical ANSYS session are:

Create the geometrical model (keypoints, lines, areas,volumes and their combinations)

Preprocessing

Define the finite element model by choosing the elementtype (including real constants), material data, andapplying boundary conditions and loads

Preprocessing / Solution

Choose a solver and compute the solution Solution

Review and analyze the results (output numbers or displayplots)

Postprocessing

It is recommended to always watch the output in the other (black) window to check if a command was accepted and how it isinterpreted.

All commands (whether written in the command line or specified over the menues) are written to a text file ("log file") which canbe saved and used for a re-modeling. Note that "everything else" (for instance re-sizing of graphics) is also written to this logfile so that it might become quite full with non-useful lines. The best is to delete unnecessary lines but it is sometimes difficult toguess which lines are important. But once you have understood most commands you will see that log files are an indispensible

tool for quick and efficient modeling!


3/10

Preprocessing commands Command atthe input line

Start PreprocessorTo get into the preprocessing part of ANSYS. From here allpreprocessingcommands are accepted.

Main Menu > Preprocessor /prep7

Geometric Model ModelingCreate Keypoint

You can use keypoints as a geometric basis of the model. You cancreate the model bottom-up, which means first the keypoints then thelines, areas, etc. Alternatively, you can create the model top-down, forexample directly create a rectangle resulting in an automatic generationof lines and keypoints. Keypoints are helpful for every geometricoperation in complex structures and also, for instance, to applyconcentrated loads and boundary conditions. They are defined bycoordinates and are numbered automatically or user defined.

Create > Keypoints

> On Working Plane> In Active CS> On Line

K,NPT,X,Y,Z

Defining Keypointsin the input line isvery efficient andthereforerecommended!

Create Lines Create > Lines> Straight Line

L,KPstart,KPend

Create Arcs Create > Lines > Arcs> Through 3 KPs> By End KPs & Rad> By Cent & Radius> Full Circle

Create Arbitrary

Creates an arbitrary polygonal area.

Create > Area > Arbitrary

> Through KPs> By Lines

A,KP1,KP2,KP3,

Create Rectangle Create > Area > Rectangle> By 2 Corners> By Centr & Cornr> By Dimensions

Create Circle Create > Area > Circle> Solid Circle> Annulus> Partial Annulus


4/10

> By End Points> By dimensions

Copy ObjectsEasy modeling of repeated geometric objects or geometries withperiodic properties. Offset depends on active coordinate system.

Copy> Keypoints> Lines> Areas

Model OperationsBoolean operations to merge geometric primitives or removeintersecting areas.

Operate Booleans-> Add> Subtract> Divide> Glue

Finite Element Structure

Define Element TypeCustomize the list of required element types (beams, plates, shells,etc.)

Element Type > Add/Edit/Delete ET,ETNr,Ename

Provide Appropriate Constants for Individual Element TypesFor example the element thickness

Real Constants > Add/Edit/Delete R,SetNr,Value1,

Define Material PropertiesFor example Youngs modulus, Poissons ratio, etc.

Material Props > Material Models

Assign AttributesAssign attributes (material properties, element types) to selected partsof the model. To make the attributes visible select numbering. Note:Bydefault, all the elements that are created with the mesh command,obtain the current (i.e. last defined) attributes.

Meshing > Mesh Attributes> Keypoints> Lines> Areas


5/10

Mesh the ModelCreate a finite element mesh for the model. Make sure to choose the

appropriate dimensionality, i.e. one-dimensional for lines (beams), two-dimensional for areas (plates, shells), three-dimensional for volumes(solid elements). Choose properties like element size, element shape,etc. prior to meshing. Usually, using the Mesh Toolinstead of theindividual commands in the mesh menu is recommendable!

Meshing > MeshTool

MeshTool Element Attributes Define material number, element type, real constants,Smart Size Element size for quick and dirty free meshingSize Controls Specify mesh density via subdivision of lines (best to

obtain structured and compatible meshes) or elementlengths

Mesh Generate the mesh, either free (automatic) or mapped(structured) with triangles or quads

Clear Clear the mesh. Has to be done for any changes in thefinite element structure!

Refine Mesh refinement in the area of chosen elements, lines,keypoints, etc.

Close Leave the MeshToolCouple Nodes

The Meshes of all individual areas have to be compatible. If this is notthe case one possibility would be to couple nodes at the intersections ofindividual mesh patches (areas) to connect these parts. Alternativelyyou can connect the areas by Boolean operations.

Coupling / Ceqn > CoincidentNodes

Loads

Loads and also boundary conditions are in general applied to the finiteelement model (i.e. after meshing). If the mesh is changed, all load datais lost!

Displacement Boundary ConditionsDefines boundary conditions for lines, areas, keypoints or nodes. Alldegrees of freedom (DOF) can be addressed separately, the prescribeddisplacement may be zero or non-zero. There is also a feature toautomatically generate symmetric and antisymmetric boundaryconditions (Caution:The program needs to guess the symmetry plane

Loads > Define Loads > Apply >Displacement

> On Lines> On Areas> On Keypoints

> On Nodes


6/10

from the given model because it does, of course, not know the realstructure. Always verify that that the generated boundary conditions are

correct).Concentrated Loads and Moments Loads > Define Loads > Apply >Force/Moment

> On Keypoints> On Nodes

Pressure LoadsTo apply pressure loads, i.e. loads that are perpendicular to the givengeometric entity

Loads > Define Loads > Apply >Pressure

> On Lines> On Areas

> On NodesDelete Loads and Boundary Conditions Loads > Delete >

> All Load Data> Displacement> Force/Moment> Pressure

Solution CommandsStart Solution Part

Now only solution commands are accepted at the input line.

Main Menu > Solution /Solu

Control the Solution ProcedureSeveral solution options, mostly for non-linear computations

Analysis Type > Soln Control

Solve ProblemSolves the current finite element system of equations (applying iterative

incremental schemes in the case of non-linear problems). Be sure toselect everything prior to solving!

Solve > Current LS


7/10

Postprocessing Commands

Start PostprocessorNow only postprocessingcommands are accepted at the input line

Main Menu > General Postproc /Post1

Generate result plotsAfter a successful computation you can create various plots of theresults like deformations, stresses, etc. You can choose between nodalsolutions mostly used for deformation results and element solutions,usually for stress plots. To change appearance of plots use plotctrls.

Plot Results> Deformed Shape> Contour Plot > Nodal Solu> Contour Plot > Element Solu> -Vector Plot- Predefined

Generate List of ResultsAll data can also be listed as numbers, e.g. nodal values for thedisplacements etc.

List Results

Work with sections / Path operationsTo display results at user defined sections, for example to performequilibrium checks, paths have to be defined. Along these paths all datacan be plotted and listed. It is also possible to do certain computations,for example to obtain a moment out of stress values and coordinates

(i.e. the excentriticity). Note:All path data will be lost when leavingPOST1 (but you can store the data in a file).To visualize a stress distribution on a path:- define a path- map the corresponding values onto the path by defining a name and

the specified value, e.g. stress in x-direction (SX). Mind the option ofaverage results over the element!

-

plot the corresponding path items either on the geometry (adjust thescale factor!) or on a special graph (which allows more items in oneplot).

- The following procedure is an example to obtain a moment for anequlibrium check: map the stresses on the path; do multiplythis itemwith the geometry distance (e.g. YG) and give it a new item-name;do integratethis new item over the geometry; the result is shown inthe output window (DOS-Box).

Note:The number of intersections, defined in the specifications at the

Path Operations> Define Path > By Nodes

> On Working Pl> By Location

> Delete Path> Plot Paths> Recall Path> Map onto Path> Plot Path Item > On Graph> Plot Path Item > On Geometry> Plot Path Item > List Path

Items> Various Calculations

> Archive Path >Store/Retrieve


8/10

beginning, control the accuracy of the plot andthe subsequentcomputations (like integration).

Work with Element TablesTo visualize certainelement results it is necessary to define elementtables. They can be plotted, listed, sorted, etc. It is possible toselectcertain elements.

Element Table> Define Table> Plot Elem Table> List Elem Table> Find Maximum/Find Minimum


9/10

Utility Menu

File File controls, handling of job name.

Write DB Log File Creates a text file (ascii) with all commands of the whole history of the current session. It is sensible to saveyour work up to a certain stage once in a while (can be used later like an undo option).

Read Input from Read commands out of text file (see above).List > Log File View the current Log File.

SelectSelecting parts of the finite element model. All subsequently issued commands refer exclusively to the currentselection. By default (at the beginning of your project) everything is selected.

Entities Select individual entities of the model (nodes, elements, lines, areas keypoints) either graphically (By Num/Pick)or with the help of certain properties (e.g. coordinates).

Everything Selects everything. Has to be done each time before starting a computation!

List Provides the possibility to list every kind of information like working-files, program-status, geometrical data, finiteelement data, etc.

Plot To plot all individual objects. Useful during modeling to organize the screen.

Multi-Plots To obtain a general replot.

PlotCtrls Controls all plot options. As there is a huge number of options, only the most important are listed below.

Pan, Zoom, Rotate Opens a window for easy controlling of zoom, viewing angle, etc. To view the entire model click FitNumbering As all objects and attributes are numbered it is sometimes useful to plot the numbers. Especially for element

attributes with different materials or real constants.Symbols Useful to display boundary conditions and forces (also as arrows instead of face outlines)Style > Contours >

Uniform Contours

It is possible to change the number of contours to control the quality of the plot.

Animate > Deformed Nice tool to animate your computation and see what happens (non-linear problems).


10/10

ResultsRedirect Plots Export into other graphic standards. Redirect to screen to switch it back.Capture Image For screenshots to compare different plots.MultiWindow Layout More than one window.

WorkPlane Work Plane controls

Display WorkingPlane

Shows working plane triad.

WP Settings Tool to control working plane as grid, activate snapping, etc.

Change Active CS to Changes coordinate system to cartesian, cylindricalor spherical for all modeling commands (lines,keypoints,). During preprocessing the status is shown in the title of the graphics window.

ParametersParameters are used as variables. For example a load can be defined as a variable Fand then set to differentvalues. Useful in general, needed for optimization problems.

Scalar Parameters Tool to define, set and check all parameters.

Documents

Ansys Quick Reference