autodesk simulation 2012 part-1

Autodesk Simulation Mechanical 2012

Part 1 Seminar Notes

II Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011

Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011 III

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Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes

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IV Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011

Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011 V

TABLE OF CONTENTS

Introduction .................................................. 1 Overview .................................................................................................................................... 1 Software Installation, Services, and Support ............................................................................ 1

Installing and Running Autodesk Simulation ..................................................................... 1 System Requirements ........................................................................................................... 2 Subscription Center ............................................................................................................... 4 Web Links .............................................................................................................................. 4 Tutorials ................................................................................................................................. 4 Webcasts and Web Courses ................................................................................................ 5 How to Receive Technical Support ...................................................................................... 5 Updates.................................................................................................................................. 6

Background of FEA ................................................................................................................... 7 What is Finite Element Analysis? ......................................................................................... 7 Basic FEA Concepts ............................................................................................................. 7 How Does Autodesk Simulation Work? ............................................................................... 9 The General Flow of an Analysis in Autodesk Simulation ................................................ 10

Stress and Strain Review ........................................................................................................ 11 Equations Used in the Solution .......................................................................................... 11 Limits of Static Stress with Linear Material Models ........................................................... 12 Mechanical Event Simulation (MES) Overcomes Limitations .......................................... 12 Hand-Calculated Example ................................................................................................. 13

Heat Transfer Review ............................................................................................................. 13 Equations Used in the Solution .......................................................................................... 13

Linear Dynamics Review ......................................................................................................... 14

Chapter 1: Using Autodesk Simulation ........................ 15 Chapter Objectives .................................................................................................................. 15 Navigating the User Interface .................................................................................................. 15

Commands ......................................................................................................................... 17 Using the Keyboard and Mouse ........................................................................................ 18 Introduction to the View Cube ............................................................................................ 19 Additional View Controls .................................................................................................... 20 Legacy View Controls in Autodesk Simulation .................................................................. 21

Steel Yoke Example ................................................................................................................ 22 Opening and Meshing the Model ....................................................................................... 22 Setting up the Model .......................................................................................................... 23 Analyzing the Model ........................................................................................................... 27 Reviewing the Results ........................................................................................................ 28 Creating an Animation ........................................................................................................ 29 Generating a Report ........................................................................................................... 29

Chapter 2: Static Stress Analysis Using CAD Solid Models ..... 33 Chapter Objectives .................................................................................................................. 33 Archiving a Model .................................................................................................................... 33 Types of Brick Elements ......................................................................................................... 34 Generating Meshes for CAD Models ...................................................................................... 35

Creating a Mesh ................................................................................................................. 36 Model Mesh Settings Options ......................................................................................... 37

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VI Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011

Tips for Modeling with CAD Solid Model Software for FEA .................................................... 39 Simplify CAD Solid Models with Autodesk Fusion .................................................................. 40 Working with Various Unit Systems ........................................................................................ 41 Loading Options ...................................................................................................................... 43

Load Cases ........................................................................................................................ 44 Constraint Options ................................................................................................................... 46

Modeling Symmetry and Antisymmetry ............................................................................. 46 Design Scenarios .................................................................................................................... 47 Load and Constraint Group ..................................................................................................... 48 Local Coordinate Systems ...................................................................................................... 49 Defining Materials and Using the Material Library Manager .................................................. 50

Adding Material Libraries and Material Properties ............................................................ 52 Examples of Loads and Constraints ....................................................................................... 54

When to Use Displacement Boundary Elements .............................................................. 54 Using Local Coordinate Systems ...................................................................................... 55 Using Surface Variable Loads ........................................................................................... 58

Exercise A: Frame Full to Quarter-Symmetry Model Comparison .......................... 63

Chapter 3: Results Evaluation and Presentation ............... 65 Chapter Objectives .................................................................................................................. 65 Background on How Results are Calculated .......................................................................... 65 How to Evaluate Results ......................................................................................................... 66

Displacement Results ........................................................................................................ 66 Stress Results ..................................................................................................................... 68 Reaction Force Results ...................................................................................................... 70 Inquiring on the Results at a Node .................................................................................... 70 Graphing the Results .......................................................................................................... 71

Presentation Options ............................................................................................................... 73 Contour Plots ...................................................................................................................... 73 Image File Creation ............................................................................................................ 77 Animating FEA Results ...................................................................................................... 78 Using the Configure Report Utility ...................................................................................... 79

Exercise B: Yoke Evaluation of Results and Generation of a Report ..................... 81

Chapter 4: Midplane Meshing and Plate Elements ............... 83 Chapter Objectives .................................................................................................................. 83 Meshing Options ..................................................................................................................... 83 Element Options ...................................................................................................................... 87

Plate Theory and Assumptions .......................................................................................... 87 Loading Options ...................................................................................................................... 88

Example of Defining the Element Normal Point ................................................................ 89 Result Options ......................................................................................................................... 92

Exercise C: Midplane Meshing and Plate Element Orientation ................................... 95

Chapter 5: Meshing ........................................... 97 Chapter Objectives .................................................................................................................. 97 Refinement Options................................................................................................................. 97

Automatic Refinement Points ............................................................................................. 97 Global Refinement Options ................................................................................................ 99

Creating Joints ....................................................................................................................... 101 Creating Bolts ........................................................................................................................ 103 Mesh Convergence Testing .................................................................................................. 105

Performing a Mesh Study ................................................................................................ 106

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Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011 VII

Exercise D: Yoke and Clevis Assembly ...................................................................... 107

Chapter 6 Introduction to Contact ........................... 109 Chapter Objectives ................................................................................................................ 109 Uses for Contact .................................................................................................................... 109 Contact Options ..................................................................................................................... 109

Setting up Contact Pairs ................................................................................................... 109 Types of Contact .............................................................................................................. 110 Friction .............................................................................................................................. 112 Surface Contact Direction ................................................................................................ 112

Contact Example ................................................................................................................... 114 How to Model Shrink Fits: ................................................................................................ 114

Shrink Fit Example ................................................................................................................ 115 Case 1 ............................................................................................................................... 117 Case 2 ............................................................................................................................... 120

Result Options ....................................................................................................................... 121 Exercise E: Yoke Model with Contact ......................................................................... 123

Chapter 7 Introduction to Linear Dynamics ................... 125 Chapter Objectives ................................................................................................................ 125 Modal Analysis ...................................................................................................................... 125 Lumped Masses .................................................................................................................... 126 Load Stiffening ....................................................................................................................... 127 Example of Natural Frequency (Modal) Analysis ................................................................. 128

Meshing the Model ........................................................................................................... 129 Adding Constraints ........................................................................................................... 130 Defining the Materials ....................................................................................................... 130 Analyzing the Model ......................................................................................................... 130 Reviewing the Results ...................................................................................................... 131

Critical Buckling Analysis ...................................................................................................... 132 Setting Up a Critical Buckling Analysis ............................................................................ 133

Result Options ....................................................................................................................... 134 Other Linear Dynamics Analyses.......................................................................................... 134

Exercise F: Concrete Platform ..................................................................................... 135

Chapter 8 Steady-State Heat Transfer ........................ 137 Chapter Objectives ................................................................................................................ 137 3-D Radiator Example ........................................................................................................... 137

Meshing the Model ........................................................................................................... 138 Setting up the Model ........................................................................................................ 139 Analyzing the Model ......................................................................................................... 140 Reviewing the Results ...................................................................................................... 141

Meshing Options ................................................................................................................... 142 Thermal Contact ............................................................................................................... 142

Element Options .................................................................................................................... 143 Rod Elements ................................................................................................................... 143 2-D Elements .................................................................................................................... 143 Plate Elements ................................................................................................................. 144 Brick and Tetrahedral Elements ...................................................................................... 145

Loading Options .................................................................................................................... 147 Nodal Loads...................................................................................................................... 147 Surface Loads .................................................................................................................. 149 Element Loads .................................................................................................................. 153 Body-to-Body Radiation ................................................................................................... 155

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VIII Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011

Controlling Nonlinear Iterations ........................................................................................ 159 Result Options ....................................................................................................................... 161

Exercise G: Infrared Detector Model ........................................................................... 163

Chapter 9 Transient Heat Transfer ........................... 165 Chapter Objectives ................................................................................................................ 165 When to Use Transient Heat Transfer .................................................................................. 165 Element Options .................................................................................................................... 165 Loading Options .................................................................................................................... 165

Load Curves ..................................................................................................................... 166 Nodal Heat Source ........................................................................................................... 167 Controlling Nodal and Surface Applied Temperatures ................................................... 168

Result Options ....................................................................................................................... 168 Exercise H: Transistor Case Model ............................................................................. 169

Chapter 10 Thermal Stress ................................... 171 Chapter Objectives ................................................................................................................ 171 Multiphysics Overview ........................................................................................................... 171 Performing a Thermal Stress Analysis.................................................................................. 172

Exercise I: Disk Brake Rotor Heat-up and Stress ...................................................... 175

Appendix A Finite Element Method Using Hand Calculations .. 177 Model Description and Governing Equations .................................................................. 179 Hand-Calculation of the Finite Element Solution ............................................................. 181 Autodesk Simulation Example ....................................................................................... 182

Appendix B Analysis Types in Autodesk Simulation ......... 185 Background on the Different Analysis Types ........................................................................ 187 Choosing the Right Analysis Type for Your Application ....................................................... 194 Combining Analysis Types for Multiphysics .......................................................................... 198

Appendix C Linear Loads and Constraints ................... 199 Nodal Loading .................................................................................................................. 201 Edge Loading ................................................................................................................... 206 Surface Loading ............................................................................................................... 207 Element Loading .............................................................................................................. 212 Constraints ........................................................................................................................ 215

Appendix D Material Model Options ......................... 219

Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011 1

Introduction Overview

This course will introduce you to the analysis products available within the Autodesk Simulation Mechanical software. These capabilities include static stress with linear material models, heat transfer, and linear dynamics analyses. The course will focus exclusively on models originating from CAD solid modeling programs. You will learn the various meshing options available for creating solid and plate elements. The available load and constraint options for each of the covered analysis types will also be presented. You will learn how to evaluate the results of the analyses and how to create presentations of the results, including images, animations and HTML reports. This course is a prerequisite to the more advanced topic of Mechanic Event Simulation (MES) covered in the Part 2 training seminar.

Software Installation, Services, and Support

Installing and Running Autodesk Simulation

The simulation software is distributed on DVDs with the exception of software for the Linux platform, which is distributed on CDs. In addition, the software may be downloaded from the Autodesk website. When you place the software DVD into a DVD-ROM drive, a launch dialog having four options will appear. If you want to set up the software on a client workstation, whether you will be using a license locked to a single computer or a network license, press the "Install Products" button. If using a network license, you must already have the license server software installed on a computer on the network. If you wish to create pre-configured deployments for installing the product on multiple client workstations, choose the "Create Deployments" command. If you want to set up the computer as a license server to control the number of concurrent users through a network, or, if you wish to install optional reporting tools, press the "Install Tools and Utilities" command. Finally, a fourth command on the launch screen, "Read the Documentation," leads to a screen from which you can access a ReadMe file and other installation and licensing guides. During the product installation process, you will need to specify your name, the name of your organization. You will also need to enter the product serial number and the product key. Otherwise, you will be limited to a 30-day trial period. To customize the installation location on your computer, the components to be installed, and/or to specify a network license server, you will have to press the "Configuration" button that appears on one of the screens during the installation process. Then, follow the prompts, provide the required information, and click the "Configuration Complete" button to continue the installation process. Any time after the installation, you will be able to start the software by using the available shortcut found in the "Start" menu folder, "All Programs: Autodesk: Autodesk Algor Simulation." The version number is included in the start menu folder name and shortcut. The name of the shortcut will depend upon which package has been purchased ("Simulation Mechanical "Simulation Multiphysics"). In the dialog that appears when the program is launched, you will be able to open an existing model or begin a new model. The simulation software will be used to create, analyze, and review the results of an analysis within a single user interface, regardless of the analysis type.

Introduction

2 Autodesk Simulation Mechanical 2012 Part 1 Seminar Notes 4/27/2011

System Requirements

We recommend the following system specifications for a Microsoft Windows platform running Autodesk Simulation software. These specifications will allow you to achieve the best performance for large models and advanced analysis types.

32-Bit 64-Bit *

Dual Core or Dual Processor Intel 64 or AMD 64, 3 GHz or higher

2 GB RAM or higher (3 GB for MES and CFD applications)

30 GB of free disk space or higher

256 MB or higher OpenGL accelerated graphics card

DVD-ROM drive

Dual Core or Dual Processor Intel 64 or AMD 64, 3 GHz or higher

8 GB RAM or higher

100 GB of free disk space or higher

512 MB or higher OpenGL accelerated graphics card

DVD-ROM drive

Supported Operating Systems:

Microsoft Windows 7 (32-bit and 64-bit editions) Microsoft Vista (32-bit and 64-bit editions) Microsoft Windows Server 2003 and Windows Server 2008 Microsoft Windows XP (32-bit and 64-bit editions) Linux **

Other Requirements (All Platforms):

Mouse or pointing device Sound card and speakers *** Internet connection *** Web browser with Adobe Flash Player 10 (or higher) plug-in ***

* We recommend usage of a 64-bit version of the operating system to run large models of any analysis type and for Mechanical Event Simulation, CFD, and Multiphysics analyses. While a 32-bit machine can be configured for larger system memory sizes, architectural issues of the operating system limit the benefit of the additional memory.

** Linux may be used as a platform for running the solution phase of the analysis only. It

may be used for a distributed processing (or clustering) platform. However, pre- and post-processing is done in the graphical user interface, which must be installed and run on a Microsoft Windows platform.

*** These requirements are due to the use of multimedia in our product line and the

availability of distance learning webcasts, software demos, and related media. Minimum system requirements and additional recommendations for Linux platforms may be found on the Autodesk website. To navigate to the Autodesk Simulation web page, access the "Help" panel from the "Getting Started" tab. Then click on the "In-Product Help" button.

Introduction


Autodesk Simulation Help

Autodesk Simulation Help is available in two placesthe In-Product Help and the Online Wiki Help, these resources contain the following information: Documentation for all of the model creation options within the user interface Documentation for all of the Autodesk Simulation analysis types Documentation for all of the result options available within the user interface Essential Skills videos (Online Wiki Help only) Step-by-step examples that illustrate many modeling and analysis options Meshing, modeling, and analysis tutorials (Online Wiki Help only) How to Access the Help Files

Select the "Getting Started" tab. Click on the "In-Product Help" button. The title page of the Autodesk Simulation Help will appear.

You can navigate through the In-Product Help or Online Wiki Help via the table of contents to the left or by using the "Search" or "Index" tabs.

Features of the Help Files

Autodesk Simulation Help is a set of compiled help files that are installed with the software but are also accessible from the Autodesk website.

Hyperlinks and a table of contents make it easy to move quickly from topic to topic.

The Help window contains a standard Internet browser toolbar, so you can move forward and backward and print with ease.

Figure I.1: Autodesk Simulation In-Product Help

Introduction


Search the Help Files using Keywords All of the pages in the Help files can be searched based on keywords.

The keywords are entered at the top of the "Search" tab on the left side of the In-Product Help or Online Wiki Help screen. Topics that match the search criteria are listed below.

Keywords are used to search the Help files. You may use single or multiple keywords.

Boolean operators (AND, OR, NEAR, and NOT) are available to enhance the search utility. Also, phrases may be enclosed in quotes to search only for a specific series of words.

Subscription Center

Along with your Autodesk Simulation software purchase, you have the option of purchasing various levels of Subscription Center access and support. The Subscription Center is accessible via the "key" icon near the right end of the program title bar and also via the "Help: Web Links" menu. Through the Subscription Center, you can download software updates, service packs, and add-on applications. You can access training media, such as topical webcasts. Finally, you can also submit technical support requests via the Subscription Center.

Web Links

Within the Getting Started tab of the ribbon, in the HELP panel, there is a "Web Links" pull-out menu. The following content can be accessed via the web links within this menu: Autodesk Simulation - product range Subscription Center Services and Support - information Discussion Group Training - course information Autodesk Labs where you may obtain free tools and explore developing technologies Manufacturing Community

Tutorials

Tutorials are available that demonstrate many of the capabilities of the Autodesk Simulation software. Each analysis is presented through step-by-step instructions with illustrations to assist the user. The tutorials are accessed from the "Help: Tutorials" command and the associated model files are in the "\Tutorials\Models" subdirectory within the program installation folder. The tutorials will appear next to the user interface. You will be able to follow the steps using the software without switching between the two windows.

Introduction


Figure I.2: Autodesk Simulation Help panel

Webcasts and Web Courses

Webcasts focus on the capabilities and features of the software, on new functionality, on accuracy verification examples, and on interoperability with various CAD solid modeling packages. These streaming media presentations are available for on-demand viewing from the Subscription Center via your web browser. Similarly, web courses are also available for on-demand viewing. Web courses are typically longer in duration than webcasts and focus on more in-depth training regarding the effective usage of your simulation software. The topics cover a wide variety of application scenarios.

For a list of available webcasts and web courses, follow the "Training" link from the home page of the Subscription Center. Choose the "Autodesk Algor Simulation" or Autodesk Simulation product in the "Browse the Catalog" list. This leads to the Autodesk Simulation e-Learning page, in which the available webcasts and web courses are listed according to topic.

How to Receive Technical Support

Technical support is reachable through several contact methods. The means you can use may depend upon the level of support that was purchased. For example, customers with "Silver" support must obtain their technical support from the reseller that sold them the software. "Gold" subscription customers may obtain support directly from Autodesk. Five ways to contact Technical Support:

Reseller: Obtain phone, fax, and/or e-mail information from your reseller.

Subscription Center: Access the Subscription Center from the link provided in the program interface. Click the Tech Support link on the left side of the page and then click on the "Request Support" link.

Autodesk Phone: (412) 967-2700 [or in USA/Canada: (800) 482-5467]

Autodesk Fax: (412) 967-2781

Autodesk E-mail: [email protected]

Introduction


When contacting Technical Support:

Have your contract number ready before contacting Technical Support.

Know the current version number of your software.

Have specific questions ready.

Remember, Technical Support personnel cannot perform, comment on, or make judgments regarding the validity of engineering work.

Updates

The software is updated with new functionality on a continual basis. The following three types of releases are provided: 1. A major version: Indicated by the four-digit year of the software release (based upon

the Autodesk fiscal year, not the calendar year)

2. A "subscription" version: Customers with a current maintenance subscription are eligible for additional releases that may be made available between major product version releases. These are designated by the addition of the word "Subscription" after the major version number.

3. A service pack: Incorporates minor improvements to a major or subscription release and is indicated by the letters "SP" and a service pack number after the major or subscription version number.

How to Determine the Software Version

Click on the "About" button in the" Help" panel. This dialog will display the version that you are using. In addition, the program title bar and the splash screen that appears at each program launch will indicate the major version number of the software. However, as with the start menu group name and program shortcut, it will not indicate the subscription and service pack variants. How to Obtain an Update

Update notifications are provided via the "Communication Center" within the user interface. The Communication Center icon is located at the right end of the program window title bar. When new information is available the state of the Communication Center icon, changes. The Communication Center provides up-to-date product support information, software patches, subscription announcements, articles, and other product information through a connection to the Internet. Users may specify how frequently the Live Update information will be polledon-demand, daily, weekly, or monthly. When a program update notification is received, the user will be given the option of downloading and installing it.

Introduction


Background of FEA

What is Finite Element Analysis?

Finite element analysis (FEA) is a computerized method for predicting how a real-world object will react to forces, heat, vibration, etc. in terms of whether it will break, wear out or function according to design. It is called "analysis", but in the product design cycle it is used to predict what will happen when the product is used. The finite element method works by breaking a real object down into a large number (1,000s or 100,000s) of elements (imagine little cubes). The behavior of each element, which is regular in shape, is readily predicted by a set of mathematical equations. The computer then adds up all the individual behaviors to predict the behavior of the actual object. The "finite" in finite element analysis comes from the idea that there are a finite number of elements in the model. The structure is discretized and is not based on a continuous solution. In any discrete method, the finer the increments, or elements, the more precise is the solution. Previously, engineers employed integral and differential calculus, which broke objects down into an infinite number of elements. The finite element method is employed to predict the behavior of objects with respect to virtually all physical phenomena: Mechanical stress (stress analysis) Mechanical vibration (dynamics) Heat transfer - conduction, convection, radiation Fluid flow - both liquid and gaseous fluids Electrostatic or MEMS (Micro Electro Mechanical Systems)

Basic FEA Concepts

Nodes and Elements

A node is a coordinate location in space where the degrees of freedom (DOFs) are defined. The DOFs of a node represent the possible movements of this point due to the loading of the structure. The DOFs also represent which forces and moments are transferred from one element to the next. Also, deflection and stress results are usually given at the nodes. An element is a mathematical relation that defines how the DOFs of one node relate to the next. Elements can be lines (beams or trusses), 2-D areas, 3-D areas (plates) or solids (bricks and tetrahedra). The mathematical relation also defines how the deflections create strains and stresses.

Introduction


Degrees of Freedom

The degrees of freedom at a node characterize the response and represent the relative possible motion of a node.

The type of element being used will characterize which DOFs a node will require.

Some analysis types have only one DOF at a node. An example of this is temperature in a thermal analysis.

A structural beam element, on the other hand, would have all of the DOFs shown in Figure I.3. "T" represents translational movement and "R" represents rotational movement about the X, Y and Z axis directions, resulting in a maximum of six degrees of freedom.

Figure I.3: Degrees of Freedom of a Node Element Connectivity Conventional Bonding

Elements can only communicate to one another via common nodes. In the left half of Figure I.3, forces will not be transferred between the elements. Elements must have common nodes to transfer loads from one to the next, such as in the right half of Figure I.4.

Figure I.4: Communication through Common Nodes Element Connectivity "Smart Bonding"

With the introduction of "Smart Bonding" it is now possible to connect adjacent parts to each other without having to match the meshes (i.e., common nodes at part boundaries are no longer mandatory). This feature is available for both CAD and hand-built models and is applicable to the following analysis types:

Static Stress with Linear Material Models Natural Frequency (Modal) Transient Stress (Direct Integration)

Figure I.5, is a pictorial example of two adjacent parts that may be connected via smart bonding. Smart bonding is disabled by default for both new and legacy models (that is, those

No Communication Communication Between the Elements Between the Elements

Introduction


created prior to implementation of the smart bonding feature). The option may be changed within the "Contact" tab of the Analysis Parameters dialog. Note that where nodal coordinates fall within the default or user-specified tolerance of each other, they will be matched in the conventional manner. Other nodes along the bonded surfaces or edges those at a relative distance greater than the tolerance will be connected by means of multipoint constraint equations (MPCs). Also note that the "Use virtual imprinting" option within the "Model" dialog of the mesh settings options will minimize the likelihood that smart bonding will be needed or will occur for CAD-based assemblies. This option attempts to imprint smaller parts on larger parts where they meet, forcing them to have identical meshes.

Figure I.5: Connection via "Smart Bonding"

Types of Elements

The actual supported and calculated DOFs are dependent upon the type of element being used. A node with translational DOFs can move in the corresponding directions and can transmit/resist the corresponding forces. A node with rotational DOFs can rotate about the corresponding axes and can transmit/resist the corresponding moments. Briefly, the general element types are as follows (more details will be given in later chapters):

Line elements: A line connecting 2 nodes (such as beams, trusses, springs, thermal rods, and others).

2-D elements: YZ-planar elements that are triangular or quadrilateral (3 or 4 lines enclosing an area).

3-D plates or shells: Planar or nearly planar elements in 3-D space. Each must be triangular or quadrilateral and they represent a thin part with a specified thickness.

Brick (solid) elements: Must be enclosed volumes with 4, 5, or 6 faces (triangular and/or quadrilateral) and with 4, 5, 6 or 8 corner nodes.

DOFs for element types:

Truss: Translation in X, Y and Z. Beam: Both translation and rotation in X, Y and Z. 2-D: Translation in Y and Z. Plate: Five degrees of freedom out-of-plane rotation is not considered. Brick: Translation in X, Y and Z.

How Does Autodesk Simulation Work?

The software transforms an engineering model with an infinite number of unknowns into a finite model.

This is an idealized mathematical model.

The model is defined by nodes, elements, loads and constraints.

Introduction


The user interface can be effectively used for the design, analysis and evaluation phases of a typical design process.

The simulation software can be extremely useful during the initial concept and design phase to identify areas that can be improved.

The simulation software can also be used to quickly evaluate a concept, saving time and engineering resources.

This does not necessarily replace the testing needed to evaluate a final design; however the goal is to minimize the prototype and testing stages of design.

The General Flow of an Analysis in Autodesk Simulation

Create a Mesh

Start the simulation program Open your model in the FEA Editor environment Select the analysis type Create your mesh Define the FEA Data

Assign the loads and constraints Define the material Define the analysis parameters Run the Analysis

Review and Present Results

Review the desired result types Save images and animations Create presentations and HTML reports

Introduction


Stress and Strain Review

Equations Used in the Solution

A complex system can be broken into a finite number of regions (elements), each of which follows the equations below:

L

AEF

dx

E

A

F

=

=

=

=

L

0

Where,

Introduction


In practice, the direct inversion is extremely difficult and sometimes unstable. In FEA, matrices can be 50,000 x 50,000 or larger. As a result, other solution methods for this linear equation have been developed. All of these methods use the basic principles of a mathematical method called Gaussian Elimination. The details of this method will not be discussed here, but may be obtained from any numerical programming text.

Since differentiation cannot be performed directly on the computer, approximation techniques are used to determine the strain in the model. Since an approximation technique is used for the strains, the finer the mesh, the better the approximation of the strain. For a linear static analysis, stress has a linear relation to strain. Therefore, the stresses will have the same accuracy as the strains. For more complex analyses, more terms are needed. The equation below is needed to represent a true dynamic analysis:

{ } [ ] { } [ ] { } [ ] { }xKxcxmf ++=

where the additional matrices and vectors are,

m = mass, x = acceleration (second derivative of displacement versus time) c = damping, x = velocity (first derivative of displacement versus time)

Limits of Static Stress with Linear Material Models

Deformations are small

Strains and rotations are small

Changes in stiffness through the model are small

Changes in boundary conditions are small

Changes in loading direction with deformations are small

Material remains in the linear elastic range

Mechanical Event Simulation (MES) Overcomes Limitations

MES supports:

Large deformations

Changing boundary conditions

Loads moving as the model moves or deforms

Nonlinear material behavior

Time-dependent loading

Large-scale motion Event visualization capabilities:

Viewing results with respect to time using the Results environment

Animation tools

Introduction


MES simulates:

Motion

Impact

Real-time observation of deformations, stresses and strains

Failure due to the following: material yielding, local and structural buckling, permanent deformations - residual stress

MES capabilities are included within the Autodesk Simulation Mechanical product. It is also included within the higher-level Autodesk Simulation Multiphysics product. For information and training regarding MES, refer to the Autodesk Simulation Mechanical Part 2 training course.

Hand-Calculated Example

Refer to Appendix A for an example of displacement and stress results for a simple truss structure. A theoretical solution using fundamental equations is presented. In addition, a hand-calculated solution based on the finite element method is presented and its results compared with those obtained by the FEA software.

Heat Transfer Review

Equations Used in the Solution

Heat transfer, as applied to FEA, is actually a conduction problem. The heat loads are boundary conditions. The primary results are a temperature profile and the heat flux through the body of the structure. Conduction is the flow of heat in the body of the structure. This is what is being solved in an FEA problem. The properties of conduction are controlled by the part definition. Only the thermal conductivity (k) is needed for a steady-state analysis. For a transient analysis, the mass density and specific heat will also be required. The governing equation is:

=L

TkAq

where: k = Thermal conductivity

A = Area T = Change in temperature L = Length

The two most common loads for a thermal analysis are convection and radiation loads. These loads are applied to a surface. The equation for the heat flow due to convection is:

( )= TThAq s

where: h = Convection coefficient A = Area Ts = Temperature of the surface T = Ambient temperature

Introduction


The equation for the heat flow due to radiation is:

( )( )44.. bTTFVAq =

where: = Emissivity which describes the surface finish for gray bodies. (If = 1.0, it is a true blackbody.)

= Stefan-Boltzmann constant for radiation

A = Area

V.F. = View factor from the surface to the infinite source

T = Ambient temperature (in units of absolute temperature)

Tb = Temperature of the node (in units of absolute temperature)

Linear Dynamics Review

Equation for Dynamic Analyses

The basic equation of dynamics is:

[m]{a}+[c]{v}+[k]{x}=0 where:

[m] = the mass matrix {a} = the acceleration vector [c] = the damping constant matrix {v} = the velocity vector [k] = the stiffness matrix {x} = the displacement vector

A natural frequency analysis provides the natural vibration frequencies of a part or assembly based on a linear eigenvalue solution. Because the above equation is solved in this linear solution, only mass and stiffness are taken into account. No damping is used. In addition, loads are ignored. As a result, actual displacement output is meaningless except to define the shape of the natural frequency mode. Note that loads are taken into account for a natural frequency with load stiffening analysis, assuming the loads produce membrane stresses that affect the stiffness of the structure. Constraints have a very significant effect on the solution. When no boundary conditions or insufficient boundary conditions are used, rigid-body movement or modes will be found. Unlike a static solution, this is acceptable in a modal analysis.


Using Autodesk Simulation Chapter Objectives

Introduction to the user interface

Commands - Ribbon Keyboard Mouse View Cube and other view controls

Complete an example of using Autodesk Simulation

Overview of launching a Simulation from Autodesk Inventor and creating a mesh Overview of adding loads and constraints to a model Overview of defining material properties Overview of performing an analysis Overview of reviewing results Overview of generating a report

Navigating the User Interface

In this section, we will introduce you to the Autodesk Simulation user interface. This interface is the same for each of the available packages, including the Simulation Mechanical and Simulation Multiphysics products. The only difference will be with regard to which advanced features or capabilities are enabled. We will begin with an overview of the major components of the graphical user interface. Then we will discuss the Ribbon, keyboard, mouse, View Cube, and additional view controls. Please note that the behavior of the keyboard, mouse and View Cube as discussed within this manual are based on the default program settings for a clean installation of the product. Many of the features to be discussed are customizable via tabs and settings within the "Application Options" dialog, reachable via the "Tools: Application Options" command. Figure 1.1 on the next page, along with the legend that follows it introduces the major components of the user interface. This manual is based on Autodesk Simulation 2012. Users of other versions may encounter differences between their version and the interface described herein.

Chapter

1

Chapter 1: Example Using Autodesk Simulation


Figure 1.1: Autodesk Simulation User Interface

Interface Legend:

A. Application Menu: Files can be opened and accessed from the Application Menu. Other commands that are available here include Merge, Export and Archive.

B. Quick Access Bar: In addition to commonly used commands, customizable, the quick access bar displays the program name and version as well as providing links to the Autodesk Subscription Center and Communication Center

C. Ribbon tab: The Ribbon tab is located just below the title bar and contains the pull-down menus.

D. Ribbon commands: The Ribbon provides the user with quick access to many commands.

E. Tree View: The tree view has unique contents for each environment of the user interface. For the FEA Editor, it shows the parts list and the units, various properties, and loads that will be used for the analysis. In the Results environment, you will see a list of results presentations and other post-processing-specific content. The components of the analysis report will be listed in the tree view within the Report environment.

F. Display Area: The display area is where the modeling activity takes place. The title bar of the window displays the current environment and the model name. The FEA Editor environment is used to create the model, add the loads and constraints and perform the analysis. The Results environment is used to view results and to create images, graphs, and animations. The Report environment will be used to produce a formal report of the analysis, including desired results presentations. View Cube and Navigate bar are also in the Display area by default.

G. Miniaxis and Scale Ruler: The miniaxis shows your viewpoint with respect to the three-dimensional working area. The scale ruler gives you a sense of the model size,

H. Status Bar: The status bar displays important messages.



Commands

Autodesk Simulation accesses program functions through the ribbon, context menus, and quick access toolbar (QAT), in addition to the Application Menu. The available commands and menus vary for each program environment (FEA Editor, Results, and Report). The Ribbon is positioned at the top and is customizable by being able to move the panel positions within the same Ribbon tab.

Figure 1.2: Autodesk Simulation Ribbon The commands are logically grouped into panels and tabs. For example, the Mesh tab includes Mesh, CAD Additions, Structured mesh and Refinement Point panels. Each panel will have specific commands, and so on. These commands can be added to the quick access toolbar, so that they can be easily accessed. This can be done by right clicking on the command in the panel and selecting "Add to Quick Access Toolbar" as shown in figure 1.2. Most of the tabs, panels, and commands will not appear until an existing model is opened or a new model is created. Figure 1.3 shows a typical context menu accessed after clicking a surface on the model and adding a load.

Figure 1.3: Autodesk Simulation Context Menu In some cases there where will be too many commands to be all displayed on the panel. In these situations you can click on the panel options button to gain access to further commands as shown in figure 1.4.

Figure 1.4: Additional Panel commands



Using the Keyboard and Mouse

The keyboard and mouse will both be used to operate within the user interface. The keyboard will be used to enter the required data for loads, constraints, material properties, and so on. It will also be used to modify the behavior of particular mouse operations. That is, certain keyboard keys, when held down, will change the behavior of the mouse. The software supports a number of different mouse configurations. This document assumes that the default template for a new installation is in effect. However, user settings, or those retained from a prior Autodesk Simulation installation, may cause the behavior to differ from that described herein. To ensure that your mouse actions follow the descriptions in this book, access the "Tools: Application Options: Mouse Options" dialog and choose the "Autodesk Simulation" template.

The left mouse button will be used to select items. How items are selected will depend upon the selection mode chosen in the "Selection: Shape" pull-out menu or Ribbon. The type of objects that are selected (such as lines, vertices, surfaces, parts, edges, or elements) will depend upon the selection mode chosen in the "Selection: Select" pull-out menu or Ribbon. Holding down the key, while left-clicking on the object, will toggle the selection state of the clicked object. That is, unselected objects will be added to the selection set and previously selected items will be removed from the selection set. Holding down the key while left-clicking will only add clicked objects to the selection set (this will have no effect on already selected items). Finally, holding both and while left-clicking will only remove clicked objects from the selection set (this will have no effect on items that are not already part of the current selection set). Pressing the right mouse button with the cursor hovering over items in the tree view will access a context menu with commands relevant to the item under the cursor. When items are currently selected, either within the tree view or display area, the right-click context menu will display commands and options that are specifically relevant to the selected items. For example, if a surface is selected, only surface-based commands will appear in the context menu. You may right-click anywhere in the display area when items are selected to access the context menu. However, to access the context menu within the tree view area, you must right-click with the cursor positioned on one of the selected headings. If a mouse has a wheel, rolling the wheel will zoom in or out on the model. Holding down the middle mouse button or wheel and dragging the mouse will rotate the model. Pressing the key, while holding the middle button and dragging the mouse, will pan the model, moving it within the display area. Pressing the key while dragging the mouse with the middle button down will zoom in and out, making the model larger as the mouse is moved upward and smaller as it is moved downward. You will likely find the use of the middle mouse button and wheel to be more convenient than choosing a command like "Rotate" or "Pan," clicking and dragging the mouse, and then pressing to exit the command. Finally, the X, Y, or Z key on the keyboard may be held down while dragging the mouse with the middle button held down. Doing so will rotate the model, as before, but constraining the rotation to be only about the corresponding X, Y, or Z global axis direction. You may also use the left and right cursor keys on the keyboard while holding down X, Y, or Z to rotate about these axes in fixed increments (15 degrees by default). The rotation increment is customizable via the "Tools: Application Options: Graphics: Miscellaneous" dialog.



Introduction to the View Cube

As is true for the mouse, the software also supports a number of different view configurations. This document assumes that the default view options template and view navigation settings for a new installation are in effect. However, user settings, or settings retained from a prior Autodesk Algor Simulation or Autodesk Simulation installation, may cause the view orientations and behavior to differ from those described throughout this document. To ensure that your view commands follow the descriptions in this book, access the "Tools: Application Options: Views Options" dialog and choose the "Autodesk Simulation" template. Next, access the "Graphics" tab of the same "Options" dialog, select "Navigation Tools" from the items listed on the left side of the dialog, and click on the "View Cube" button. Click the "Restore Defaults" button followed by "OK" to exit the "View Cube Properties" dialog. Finally, click the "Steering Wheel" button. Click the "Restore Defaults" button followed by "OK" to exit the "Steering Wheels Properties" dialog. Click "OK" to exit the "Options" dialog. Users of other Autodesk products, such as AutoCAD or Autodesk Inventor will likely already be familiar with the View Cube and associated additional view controls. The View Cube will be located in the upper right corner of the display by default but may be relocated. The appearance will change depending upon whether the view is aligned with a global plane and whether the cursor is near the cube or not. The View Cube, in its various appearances, is shown in Figure 1.5.

Figure 1.5: View Cube Appearance The six standard view names, as labeled on the cube faces, are the Top, Bottom, Front, Back, Left, and Right. These may be selected by clicking near visible face names on the cube, as shown in Figure 1.5 (b) or by clicking the triangular arrows pointing towards the adjacent faces, as shown in Figure 1.5 (c), which shows the cursor pointing to the arrow for the Bottom view. In addition, there are clickable zones at each corner and along each edge of the View Cube. Clicking on a corner will produce an isometric view in which that particular corner is positioned near the center and towards you. Clicking an edge will produce an oblique view, rotated 45 degrees, Half-way between the views represented by the two adjacent faces. When the cursor is near the View Cube, a "Home" icon will appear above it and to the left, providing easy access to the home view. This is an isometric view having the corner between the Front, Right, and Top Faces centrally positioned and towards you by default. The home view may be redefined by right-clicking the Home icon and choosing the "Set Current View as Home" command while viewing the model positioned as desired. When one of the six standard views is active and the cursor is near the View Cube, two curved arrows will appear above and to the right of the cube, as seen in Figure 1.5 (c). These

(a) Cursor not near the View Cube

(b) Cursor on View Cube (view not aligned to a standard face)

(c) Cursor on View Cube (standard face view)



are used to rotate the model to one of the four possible variants of the particular standard view. Each click of an arrow will rotate the model 90 degrees in the selected direction. When the face being viewed is changed via the View Cube, the model may move to the selected view in the manner that requires the least amount of motion. For example, say we are first looking at the Right view, with the word "Right" positioned upright (that is in the normal reading position). Now, if we click the downward arrow above the cube, the model will rotate 90 degrees to reveal the top face. The Top view will be rotated 90 degrees clockwise from the upright orientation (that is, the word "Top" will read in the vertically downward direction). Activating the "Keep scene upright" option will cause the Front, Back, Left, and Right views to automatically be oriented in the upright position (Top above, Bottom below) when changing to any of these views. You may, however, rotate the view after initial selection, if desired. Go to "Tools: Application Options: Graphics: Navigation Tools: View Cube" to locate the "Keep scene upright" setting. It is activated by default. The point of this discussion is that whenever a new face is selected using the View Cube, the resultant view rotation may differ, depending upon the prior position of the model. If the resultant orientation is not what is desired, simply click one of the curved arrows to rotate the view.

Additional View Controls

Immediately below the View Cube is a pallet of additional view controls. This consists of seven tools, each of which may be individually enabled or disabled. All are on by default. Figure 1.6 shows the view control pallet. From top to bottom, the seven tools are as follows:

Steering Wheels Pan Zoom Orbit Center Previous View Next View

Each of these icons, except for the Previous and Next commands, function as a toggleclicking it once to activate a command and again to deactivate it. Several of the tools, such as Pan, Previous, and Next are self-explanatory The "Zoom" tool includes a fly-out menu allowing the choice of one of four different zooming modesZoom, Zoom (Fit All), Zoom (Selected), and Zoom (Window). The first of these causes the model to become larger as the cursor is moved upward in the display area and smaller when it is moved downward. The Fit (All) mode encloses the extents of the whole model. After selecting objects in the display area, the Zoom (Selected) tool fits the selected items into the display area. Finally, after selecting the Zoom (Window) tool, you click and drag the mouse to draw a window defines the area you wish to expand to fill the display area. The "Orbit" tool has two variants, selectable via a fly-out menuOrbit, and Orbit (Constrained). The former allows the model to be rotated freely in any direction. The Constrained option causes the model to rotate only about the global Z-axis, similar to pressing the Z key while dragging the mouse with the middle button depressed. The "Center" tool is used to center a point on the model within the display area. Click with the mouse to specify the desired center point after selecting the Center command. This point also becomes the display pivot point, about which the model pivots when being rotated.

Fig

ure

1.6:

Add

itio

nal V

iew

Con

trol

s P

alle

t



The "Steering Wheel" tool is customizable and, in its default setting, produces the Full Navigation Wheel shown in Figure 1.7. The full navigation wheel floats above the model view, following the cursor position. It provides an additional access method for several functions found elsewhere on the view tools pallet as well as a few additional functions.

Figure 1.7: Full Navigation Wheel The "Rewind" button on the navigation wheel presents a timeline of thumbnails representing various views that have been used during the modeling session. Simply release the mouse button with the cursor positioned at the thumbnail representing the view to which you wish to jump. This is more convenient than pressing the previous or next view buttons multiple times. For additional information concerning these view controls, consult the In-Product Help or Online Wiki Help.

Legacy View Controls in Autodesk Simulation

Traditional view controls and options are also provided via the View tab of the command ribbon at the top of the screen. Options for displaying or hiding the mesh or model shading may be found here as well as eight pre-defined, standard view orientations. The orientations will depend upon the currently active Views Options template (previously discussed in the "Introduction to the View Cube" section of this chapter). There is also a "User-defined Views" dialog that may be used to save, modify, or restore custom views. Additional capabilities include a local zoom feature and display toggles for the scale ruler, mini axis, and perspective mode. The "Local Zoom" feature displays a small rectangle that represents the area to be magnified. A larger rectangle shows an overlay of the magnified region. You may click on and drag the local zoom window to position it anywhere on the model within the display area. The size of the local zoom area and magnified overlay and also the zoom level can be customized via the "Application Menu: Options: Graphics: Local Zoom" dialog. For additional information concerning the legacy view controls, consult the In-Product Help or Online Wiki Help.



Steel Yoke Example

This example is an introduction to static stress analysis with linear material models. The example will give step-by-step instructions to create a mesh and analyze a three-dimensional (3-D) model of a steel yoke under an applied force. There are three sections:

Setting up the model Open the model in the FEA Editor environment and create the mesh on the model. Add the necessary forces and boundary conditions and define the model parameters. Visually check the model for errors with the Results environment.

Analyzing the model Analyze the model using the static stress with linear material models processor.

Reviewing the results View the displacements and stresses graphically using the Results environment. Use the Inventor solid model, yoke.ipt, located in the "Chapter 1 Example Model\Input File" folder in the class directory (or extracted to your computer from the solutions archive) to create a simple model of the steel yoke shown in Figure 1.8. The right half of the small hole will be fixed. A force of 800 pounds will be applied to the left half of the large hole and acting towards the left, as shown in the figure. The yoke is made of Steel (ASTM-A36). Analyze the model to determine the displacements and stresses.

Figure 1.8: Steel Yoke Model

Opening and Meshing the Model

The FEA Editor environment is used to create a mesh for all solid models. You can open CAD solid models from any of the CAD solid modelers that Autodesk Simulation supports. You can also open models of any of the universal CAD formats that are supported. Here we are going to access Autodesk Simulation directly from Autodesk Inventor.

"Start: All Programs: Autodesk: Autodesk Inventor 2012: Autodesk Inventor Professional 2012"

Press the Windows "Start" button and access the "All Programs" pull-out menu. Select the "Autodesk" folder and then the "Autodesk Inventor 2012" pull-out menu. Choose the "Autodesk Inventor Professional 2012 software" command.

"Getting Started: Launch: Open"

Click on the "Open" button in the Launch panel. Alternatively you select Open from the quick access toolbar or Application Menu.

"Autodesk Inventor Parts (*.ipt)"

Select the "Autodesk Inventor Parts (*.ipt) option in the "Files of type:" drop-down box.

"Yoke.ipt" Select the file "Yoke.ipt in the Chapter 1 Example Model \Input File directory.

Open Press the Open button.



Mouse Select "Yes" to accept the warning

"Add-Ins: Start Simulation: Autodesk Simulation"

Select the "Add-Ins" tab. Click on the "Start Simulation button in the "Autodesk Simulation" panel.

"Linear: Static Stress with Linear Material Models" "OK"

A dialog will appear asking you to choose the analysis type for the model. From the pull-out menu, choose "Linear: Static Stress with Linear Material Models" and press the "OK" button.

The model will appear in the FEA Editor environment.

"Mesh: Mesh: 3D Mesh Settings"

Select the "Mesh" tab. Click on the "3D Mesh Settings" button in the "Mesh" panel.

"Mesh model" Press the "Mesh model" button to create a mesh with the default options.

"View: Navigate: Orbit"

Select the "View" tab. Click on the "Orbit" button in the "Navigate" panel. Can also access Orbit from the Navigate Bar.

Mouse

Click left mouse button and drag the mouse to rotate the model and inspect the mesh all around it. This mesh appears to be acceptable. When done inspecting the mesh, position the model so that you can see the inside of the small hole as shown in Figure 1.9. These surfaces will be constrained.

Press to exit the rotate command.

Figure 1.9: Yoke Rotated to Select Constrained Surfaces

Setting up the Model

The FEA Editor environment is also used to specify all of the element and analysis parameters for your model and to apply the loads and constraints. When you initially come into the FEA Editor environment with the yoke model, you will notice a red X on certain headings in the tree view. This signifies that this data has not yet been specified. You will need to eliminate all of the red Xs before analyzing the model. Since you have created a solid mesh, the



"Element Type" heading in the tree view is already set to "Brick" and the default "Element Definition" parameters have been accepted.

Adding Constraints

Constraints describe how a finite element model is tied down in space. If an object is welded down so that it can neither translate nor rotate, the object is fully constrained.

"Selection: Shape: Point"

Select the "Selection" tab. Make sure the "Point" button is selected in the "Shape" panel.

"Selection: Select: Surfaces"

Also make sure the "Surfaces" button is selected in the "Select" panel.

Mouse Click one of the surfaces on the right side of the small hole as oriented in Figure 1.9.

Mouse Holding down the key, click on the other surface on the right side of the small hole.

"Setup: Constraints: General Constraint"

Select the "Setup" tab. Click on the "General Constraint" button in the "Constraints" panel.. The dialog shown in Figure 1.10 will appear.

Figure 1.10: Surface Boundary Condition Dialog

"Fixed"

Press the "Fixed" button. Note that all 6 of the checkboxes in the "Constrained DOFs" section to the left are activated. This means that the nodes on this surface will be totally constrained.

"OK"

Press the "OK" button to apply these boundary conditions. Now there will be green triangles on the nodes of the surface that was selected. This signifies a fully constrained boundary condition.



Adding Forces to the Model

In this section, you will add the 800 lb force in the X direction to the large hole.

Mouse

Click and drag using the middle mouse button to rotate the model. Position it so that you can see the surfaces of the large hole where the load is to be applied (that is, the two quarter surfaces at the left side of the hole).

Mouse Click on one of the surfaces on the left interior of the large hole to select it.

Mouse Holding down the key, click on the other surface on the left side of the large hole.

"Loads: Forces" Click on the "Force" button in the "Loads" panel.. The dialog shown in Figure 1.11 will appear.

Figure 1.11: Surface Forces Dialog

-400

Type "-400" in the "Magnitude" field to add two forces of 400 pounds each in the negative X direction to the surfaces. This force will be evenly distributed across each surface. They will combine to produce the desired 800 pound load.

"X" Select the "X" radio button in the "Direction" section to add surface forces in the X direction.

"OK" Press the "OK" button to apply these surface forces. Now there will be green arrows on the surfaces that were selected. They are pointed in the negative X direction.

"View: Navigate: Top View"

Select the "View" tab. Click on the options button to the bottom of "Orientation" button in the "Navigate" panel. Select "Top View" from the pull-out menu. The model should now look like Figure 1.12. The View Cube can also be used to access the views



Figure 1.12: Yoke after Boundary Conditions and Loads are Applied

Assigning the Parameters

Once the model has been constructed and the loads and constraints have been applied, use the FEA Editor environment to specify material properties.

Mouse Right-click on the "Material" heading for Part 1.

"Edit Material" Select the "Edit Material" command. The "Element Material Selection" dialog will appear.

"Steel (ASTM-A36)" Highlight the "Steel (ASTM-A36)" item from the list of available materials as shown in Figure 1.13.



Figure 1.13: Element Material Selection Dialog

"Edit Properties" Press the "Edit Properties" button to view the material properties associated with this steel.

"OK" Press the "OK" button to exit the "Element Material Specification" dialog.

"OK" Press the "OK" button to accept the information entered in the "Element Material Selection" dialog for Part 1.

Mouse Accept the warning to override default material defined within Inventor.

"Analysis: Analysis: Check Model"

Select the "Analysis" tab. Click on the "Check Model" button in the "Analysis" panel.

"Tools: Environments: FEA Editor"

Select the "Tools" tab. Press the "FEA Editor" button in the "Environments" panel.

"View: Orientation: Isometric View"

Select the "View" tab. Click on the options button to the bottom of "Orientation" button in the "Navigate" panel. Select "Isometric View" from the pull-out menu.

Analyzing the Model

"Analysis: Analysis: Run Simulation"

Select the "Analysis" tab. Click on the "Run Simulation" button in the "Analysis" panel. When completed, the model will be displayed in the Results environment and the von Mises stress will be displayed, as shown in Figure 1.14 below. Note the maximum stress value.



Figure 1.14: Yoke Model as Displayed in the Results Environment

Reviewing the Results

"Results Contours: Stress: von Mises"

Note the maximum von Mises value.

"Results Contours: Displacement: Displacement"

Select the "Results Contours" tab. Click on the "Displacement" button in the "Displacement" panel. Note the maximum displacement magnitude.

The maximum von Mises stress and maximum deflection should closely match the values in the table below.

Maximum von Mises Stress (psi)

Maximum Displacement (in)

~1,900 ~0.0004

Viewing the Displaced Shape

Viewing the displaced shape is always the best way to get an overall understanding of how the model reacted to the applied load. A displaced model alone or a displaced model overlaid with a undisplaced model can be displayed.



"Results Contours: Displaced Options"

Click on options next to "Show Displaced" button in the "Displacement" panel. Then select "Displaced Options" button.

"Transparent" Select the "Transparent" radio button in the "Show Undisplaced Model As" section.

Mouse Press the button in the upper right corner of the

"Displaced Model Options" dialog.

Creating an Animation

" Results Contours: Captures: Start Animation"

Select the "Results Contours" tab. Click on the "Start Animation" button in the "Captures" panel.

"Captures: Stop Animation"

Click on the "Stop Animation" button in the "Captures" panel.

The preceding steps animated the results within the display area but did not create an animation file that we can place in our report. In the following steps, we will export an animation file that can be included in the report or copied to and played on any computer.

"Animation: Save As AVI"

Click on the "Start Animate" button in the "Captures" panel. Then select "Save As AVI" option.

"von Mises Stress Animation" Rather than using the default file name, type "von Mises Stress Animation" into the "File name:" field.

"Save" Press the "Save" button to save the animation to an AVI file format.

"No" Press the "No" button when asked if you want to view the animation.

Generating a Report

In this section, you will automatically create an HTML report using the Report Configuration Utility.

"Tools: Report"

Select the "Tools" tab. Click on the "Report" button in the "Environments" panel..

"Tools: Setup: Configure"

Select the "Configure" button in the "Setup" panel. This will open the dialog shown in Figure 1.15.



Figure 1.15: Report Configuration Utility

NOTE: Clicking on any of the checkboxes will toggle the inclusion state of the item (i.e. whether it is to be included or excluded from the HTML report). When selecting included portions of the report, to modify them. Click on the item name and not on the checkbox. This will select the item without toggling the checkbox state.

Mouse Activate the checkbox next to the "Logo" heading. This will include the default Autodesk logo at the top of the report.

Note that you may also customize the logo by browsing to and selecting your own image file. Several different image file formats are supported. The logo size and alignment may also be adjusted by right-clicking on it and choosing the "Format Image" command. You may also select the image and then click and drag the handles that appear around the image border while it is selected to resize it.

Mouse Select the "Project Name" heading.

Mouse: Yoke Design

Click and drag the mouse to select the text, "Design Analysis" and type "Yoke Design" to replace it.

Mouse: Analysis of Yoke under 800 lbf Loading

Click and drag the mouse to select the text, "Project Title Here" and replace this text by typing "Analysis of Yoke under 800 lbf Loading".

Mouse Select the "Title and Author" heading. Your Name Type your name into the "Author" field.

Your Department Type your department name into the "Department" field.

Mouse Select the "Reviewer" heading.

Person who checked model Type the name of the person who checked the model into the "Reviewer" field.

Department of person who checked the model

Enter the name of the department of the person who checked the model into the "Department" field.



Passed all FEA tests Type "Passed all FEA tests" into the "Comments" field.

Mouse Deselect the "Executive Summary" item by clicking on the associated checkbox. This item will be excluded from the report.

NOTES: Text can be added as desired within the "Executive Summary" section using the built-in word

processor features. A variety of font and paragraph styles are included, such as bullet or numbered lists, tables, tabs, and various text justification settings.

The following sections are automatically generated and cannot be modified. The analyst may

only include or exclude these items or alter their order of appearance within the report:

Summary Analysis Parameter

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