Preface

Preface (UP19980818 )

Topics in This Manual

This manual, the ANSYS Basic Analysis Procedures Guide, describes how to apply loads to a finite element model, solve the model, and analyze the results. It also explains how to use the ANSYS program's graphics tools to tailor displays of models and analysis results, so that they provide the information you want in a format that is most useful or meaningful to you.

Topics in Other ANSYS Manuals

Three other manuals in the ANSYS documentation set explain how to use various capabilities of the ANSYS program:

The ANSYS Modeling and Meshing Guide explains techniques for building a finite element model.
The ANSYS Operations Guide discusses basic procedures for using the ANSYS product: how to start it and stop it, how to conduct an ANSYS session, hints and tips for using the product's graphical user interface (GUI), etc.
The ANSYS Advanced Analysis Techniques Guide describes procedures and topics commonly used by ANSYS users who have extensive experience in using the program, in complex analyses, or both. Among other topics, this document discusses how to optimize designs, how to use submodeling and substructuring to enhance analyses of problems that are large or require extensive computer resources, and how to use the ANSYS Parametric Design Language to create parameters and macros, and other items that simplify model building

Additional manuals in the documentation set explain how to perform analyses for various disciplines, describe theory and ANSYS implementation of it, and ANSYS command syntax.

Conventions This Manual Uses

This manual uses several conventions to help you identify various types of information:

Type style or text

Indicates

BOLD

Uppercase, bold text indicates command names (such as K, DDELE, etc.)

Bold>Bold

Bold text in mixed case indicates a menu path, which is a series of menu picks used to access a command from the GUI. One or more angle brackets (>) separate menu items in a menu path. Frequently in text, an ANSYS command is followed by its GUI equivalent in parentheses:
the *GET command (Utility Menu>Parameters>Get Scalar Data)

ITALICS

Uppercase italic letters indicate command arguments for numeric values (such as VALUE, INC, TIME). On some commands, non-numeric convenience labels (for example, ALL and P) can also be entered for these arguments.

Italics

Mixed case italic letters indicate command arguments for alphanumeric values (for example, Lab or Fname). The manual also uses italic text for emphasis.

TYPEWRITER

Typewriter font indicates command input listings, ANSYS output listings, and text that an ANSYS user enters.

Note-

This text introduces note paragraphs. A note contains information that supplements the main topic being discussed.

Caution:

Paragraphs that begin with the word "Caution" in bold warn you about actions or situations that potentially may cause problems or unexpected ANSYS behavior or results.

Warning:

Paragraphs that begin with the word "Warning" in bold warn you about actions or situations that can shut down the ANSYS program, can damage files, etc.

The ANSYS Product Family

In addition to ANSYS/Multiphysics, ANSYS, Inc. offers a variety of derived products (listed below) with features tailored for specific finite element analysis disciplines. Manuals in the ANSYS documentation set (particularly the ANSYS Commands Reference and ANSYS Elements Reference), frequently use two-character codes to indicate which ANSYS products can use a specific capability, command, element, etc. This information is important, because some command arguments and element KEYOPT settings have defaults in the derived products that differ from those in the ANSYS/Multiphysics product.

The "Product Restrictions" sections of the descriptions of the affected commands and elements clearly document such cases. If you plan to use a derived product input file in the ANSYS/Multiphysics product, explicitly input these settings in the derived product rather than using the default. Otherwise, your file will not behave as you expect. The following table summarizes the primary ANSYS derived products and their capabilities. (The Y indicates which capabilities each product offers.) The key preceding the capabilities table lists each ANSYS product code and its related ANSYS product.

Capabilities Offered by Each ANSYS Product

Code

Product

Code

Product

Code

Product

Mp

ANSYS/Multiphysics

Th

ANSYS/Thermal

PP

ANSYS/PrepPost

Me

ANSYS/Mechanical

FL

ANSYS/FLOTRAN

ED

ANSYS/ED

St

ANSYS/Structural

E3

ANSYS/Emag 3-D

Dy

ANSYS/LS-DYNA

LP

ANSYS/LinearPlus

E2

ANSYS/Emag 2-D

DP

ANSYS/LS-DYNA PrepPost

Capability

ANSYS Product Codes

Mp

Me

St

LP

Th

Fl

E3

E2

PP

ED

Dy

DP

Linear Stress:

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Structural Nonlinear:

Geometric

Y

Y

Y

Y

-

-

-

-

-

Y

Y

-

Material

Y

Y

Y

-

-

-

-

-

-

Y

Y

-

Element

Y

Y

Y

Y

-

-

-

-

-

Y

Y

-

Dynamic Analysis:

-

-

-

-

-

-

-

-

-

-

-

-

Modal

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Spectrum

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Harmonic

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Random Vibration

Y

Y

Y

-

-

-

-

-

-

Y

-

-

Structural Transient:

Linear

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Nonlinear

Y

Y

Y

-

-

-

-

-

-

Y

Y

-

Buckling:

Linear

Y

Y

Y

Y

-

-

-

-

-

Y

-

-

Nonlinear

Y

Y

Y

-

-

-

-

-

-

Y

Y

-

Substructuring:

Y

Y

Y

-

-

-

-

-

-

Y

-

-

Thermal:

Steady State

Y

Y

-

-

Y

Y

-

-

-

Y

-

-

Transient

Y

Y

-

-

Y

Y

-

-

-

Y

-

-

Conduction

Y

Y

-

-

Y

Y

-

-

-

Y

-

-

Convection

Y

Y

-

-

Y

Y

-

-

-

Y

-

-

Radiation

Y

Y

-

-

Y

Y

-

-

-

Y

-

-

Phase Change

Y

Y

-

-

Y

-

-

-

-

Y

-

-

CFD:

Steady State

Y

-

-

-

-

Y

-

-

-

Y

-

-

Transient

Y

-

-

-

-

Y

-

-

-

Y

-

-

Incompressible

Y

-

-

-

-

Y

-

-

-

Y

-

-

Compressible

Y

-

-

-

-

Y

-

-

-

Y

-

-

Laminar

Y

-

-

-

-

Y

-

-

-

Y

-

-

Turbulent

Y

-

-

-

-

Y

-

-

-

Y

-

-

Natural Convection

Y

-

-

-

-

Y

-

-

-

Y

-

-

Forced Convection

Y

-

-

-

-

Y

-

-

-

Y

-

-

Conjugate Heat Transfer

Y

-

-

-

-

Y

-

-

-

Y

-

-

Multiple Species

Y

-

-

-

-

Y

-

-

-

Y

-

-

Electromagnetics:

Magnetostatics

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Low Frequency Transient

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Low Frequency AC Harmonic

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Electrostatics

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Current Conduction

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Circuit Coupled

Y

-

-

-

-

-

Y

Y

-

Y

-

-

High Frequency Modal

Y

-

-

-

-

-

Y

-

-

Y

-

-

High Frequency AC Harmonic

Y

-

-

-

-

-

Y

-

-

Y

-

-

Field and Coupled-Field:

Acoustics

Y

Y

-

-

-

-

-

-

-

Y

-

-

Acoustics-Structural

Y

Y

-

-

-

-

-

-

-

Y

-

-

Electric- Magnetic

Y

-

-

-

-

-

Y

Y

-

Y

-

-

Fluid- Structural

Y

-

-

-

-

-

-

-

-

Y

-

-

Fluid-Thermal

Y

-

-

-

-

Y

-

-

-

Y

-

-

Magnetic- Fluid

Y

-

-

-

-

-

-

-

-

Y

-

-

Magnetic-Structural

Y

-

-

-

-

-

-

-

-

Y

-

-

Magnetic-Thermal

Y

-

-

-

-

-

-

-

-

Y

-

-

Piezoelectrics

Y

Y

-

-

-

-

-

-

-

Y

-

-

Thermal-Electric

Y

Y

-

-

Y

-

-

-

-

Y

-

-

Thermal-Structural

Y

Y

-

-

-

-

-

-

-

Y

-

-

Electro-Magnetic-ThermalStruct

Y

Y

-

-

-

-

-

-

-

Y

-

-

Solvers:

Frontal

Y

Y

Y

Y

Y

-

Y

Y

-

Y

-

-

Sparse

Y

Y

Y

Y

Y

-

Y

Y

-

Y

-

-

Iterative

Y

Y

Y

Y

Y

Y

Y

Y

-

Y

-

-

Explicit

-

-

-

-

-

-

-

-

-

-

Y

-

Preprocessing:

IGES Geometry Transfer

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Solid Modeling

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Meshing

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Loads and Boundary Conditions

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Postprocessing:

Contour Displays

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Vector Displays

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Animation

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Results Listing

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Output (VRML, Postscript,TIFF)

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Submodeling:

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

-

-

Optimization:

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

-

ANSYS Parametric Design Language (APDL):

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Features of the multi-purpose ANSYS program include finite element analysis capabilities for all engineering disciplines-structural, mechanical, electrical, electromagnetic, electronic, thermal, fluid, and biomedical. The basic ANSYS program is available in two versions with different names:

ANSYS/Multiphysics is the "full" ANSYS program plus the electromagnetics and FLOTRAN add-on options. It does not include the LS-DYNA option. (You must order the LS-DYNA option separately.)
ANSYS/Mechanical has the linear stress, structural, dynamic analysis, buckling, substructuring, heat transfer, thermal, acoustics, and piezoelectrics capabilities of ANSYS/Multiphysics but excludes the three add-on options: electromagnetics, LS-DYNA explicit dynamics, and FLOTRAN computational fluid dynamics (CFD).

Add-On Electromagnetics Capability (2-D and 3-D versions)

This capability lets you perform field analyses in electromagnetics (static and low-frequency applications), electrostatics, current conduction, circuit simulation, and coupled circuit-electromagnetic simulation. You may also perform coupled magnetic-thermal analyses (for example, induction heating) and magnetic-structural analyses (such as armature motion). If the add-on FLOTRAN CFD capability also is available, you can simulate electromagnetic-CFD coupling.

Add-On FLOTRAN CFD Capability

Using this capability, you can solve fluid flow and heat transfer analyses that involve mass transport using the Navier-Stokes equation to determine the flow characteristics of a fluid medium, including pressure drop, velocity, lift and drag forces, and heating or cooling effects. (You can solve heat transfer problems that do not involve mass transport with ANSYS/Mechanical.) You can analyze both Newtonian and non-newtonian fluids. You can also solve a wide variety of fluid flow problems: laminar and turbulent flow, incompressible and compressible fluids (subsonic, transonic, and supersonic regimes), and steady-state and transient analyses. Heat transfer capabilities include forced, free, and mixed convection as well as pure conduction and conjugate heat transfer. Momentum source terms enable you to model the effects of fans or screens without modeling their exact geometry.

Add-On LS-DYNA Explicit Dynamics Capability

This optional capability provides ANSYS users with an interface to the LS-DYNA explicit finite element analysis program. LS-DYNA's explicit solution capability provides fast solutions for large deformation dynamics and complex contact problems. It also supports transient dynamic analysis and the analysis of nonlinearities, such as eroding contact or metal forming applications. Applications of the ANSYS/LS-DYNA option include crashworthiness analysis for all transportation industries, metal forming simulation, nonlinear buckling analyses, and sonic wave propagation analyses.

ANSYS Derived Products

In addition to the ANSYS/Multiphysics program and its add-on capabilities, a series of ANSYS derived products is available. These products are subsets of ANSYS derived directly from the ANSYS/Multiphysics program.

ANSYS/Mechanical is designed for both linear and nonlinear, structural and thermal, static, and dynamic/transient analyses. It enables users to solve a wide variety of analyses in mechanical and civil engineering applications. As mentioned previously, ANSYS/Mechanical has the linear stress, structural, dynamic analysis, buckling, substructuring, heat transfer, thermal, acoustics, and piezoelectrics capabilities of ANSYS/Multiphysics but excludes the three add-on options: electromagnetics, LS-DYNA explicit dynamics, and FLOTRAN computational fluid dynamics (CFD).

The ANSYS/Structural product supports the following types of structural analyses: structural static, modal, harmonic response, transient dynamic, spectrum, buckling, nonlinear structural, and p-method structural static analysis. Useful for many civil and mechanical engineering applications, the product also enables you to solve fracture mechanics problems and model composites and to perform fatigue evaluations. The ANSYS/Structural product does not include the LS-DYNA explicit dynamics, thermal, electromagnetic, CFD, acoustics, or piezoelectric capabilities of ANSYS.

The ANSYS/LinearPlus product enables you to do linear static and dynamic structural analyses. Dynamic analyses include modal, harmonic, transient, and spectrum analyses. Although it is limited mostly to linear structural solutions, ANSYS/LinearPlus has some nonlinear capabilities such as large deflection and stress stiffening for some elements and node-to-node contact elements.

The ANSYS/Thermal product has steady-state and transient thermal analysis capabilities. ANSYS/Thermal allows for combined thermal-electric analyses for the elements supported in the product; it provides solution capabilities for a variety of mechanical and electrical engineering applications.

ANSYS/Emag is an electromagnetic field simulation product designed for static and low-frequency electromagnetics, electrostatics, current conduction, circuit simulation, and coupled circuit-electromagnetic simulation. You can use the 3-D version for both three-dimensional and two-dimensional models. The 2-D version supports only two-dimensional (planar or axisymmetric) models. When combined with an ANSYS structural or thermal product, ANSYS/Emag also enables you to do coupled magnetic-thermal analyses (such as induction heating) and magnetic-structural analyses (such as armature motion). If the add-on FLOTRAN CFD capability is available, you can also simulate electromagnetic-CFD coupling.

ANSYS/FLOTRAN is a CFD (computational fluid dynamics) product for fluid flow and heat transfer analyses. It has the same capabilities as the add-on FLOTRAN CFD capability described above.

ANSYS/DYNAPrepPost is a preprocessing and postprocessing product that, like the add-on LS-DYNA option described above, enables you to perform explicit dynamics analyses. The difference between ANSYS/DYNAPrepPost and the ANSYS/LS-DYNA add-on option is that the add-on option provides the LS-DYNA solver and pre- and postprocessing capabilities, while ANSYS/DYNAPrepPost offers only an interface to LS-DYNA with preprocessing and postprocessing.

ANSYS/PrepPost is a preprocessing and postprocessing product designed for building large models and moving them to a different, usually more powerful, computer for solution. It has all the preprocessing and postprocessing capabilities of ANSYS/Multiphysics.

ANSYS/ED is an educational version of ANSYS designed for corporate training programs, academic institutions, and self-study. It has all the capabilities of ANSYS/Multiphysics, including electromagnetics and FLOTRAN CFD. The primary difference between ANSYS/Multiphysics and ANSYS/ED is that the educational product limits the size of the model that you can solve. In addition, ANSYS/ED does not include composites, and you cannot relink the product to include user features.

Type style or text	Indicates
BOLD	Uppercase, bold text indicates command names (such as K, DDELE, etc.)
Bold>Bold	Bold text in mixed case indicates a menu path, which is a series of menu picks used to access a command from the GUI. One or more angle brackets (>) separate menu items in a menu path. Frequently in text, an ANSYS command is followed by its GUI equivalent in parentheses: the GET command (Utility Menu>Parameters>Get Scalar Data*)
ITALICS	Uppercase italic letters indicate command arguments for numeric values (such as VALUE, INC, TIME). On some commands, non-numeric convenience labels (for example, ALL and P) can also be entered for these arguments.
Italics	Mixed case italic letters indicate command arguments for alphanumeric values (for example, Lab or Fname). The manual also uses italic text for emphasis.
`TYPEWRITER`	Typewriter font indicates command input listings, ANSYS output listings, and text that an ANSYS user enters.
Note-	This text introduces note paragraphs. A note contains information that supplements the main topic being discussed.
Caution:	Paragraphs that begin with the word "Caution" in bold warn you about actions or situations that potentially may cause problems or unexpected ANSYS behavior or results.
Warning:	Paragraphs that begin with the word "Warning" in bold warn you about actions or situations that can shut down the ANSYS program, can damage files, etc.

Code	Product	Code	Product	Code	Product
Mp	ANSYS/Multiphysics	Th	ANSYS/Thermal	PP	ANSYS/PrepPost
Me	ANSYS/Mechanical	FL	ANSYS/FLOTRAN	ED	ANSYS/ED
St	ANSYS/Structural	E3	ANSYS/Emag 3-D	Dy	ANSYS/LS-DYNA
LP	ANSYS/LinearPlus	E2	ANSYS/Emag 2-D	DP	ANSYS/LS-DYNA PrepPost