Autodesk Fatigue Wizard

The Fatigue Wizard software enables CAE engineers of any experience level to utilize results of a finite element analysis to carry out sophisticated and accurate fatigue life calculation. CAE engineers with over 30 years combined experience and knowledge of finite element analysis and durability assessment developed it.

The Fatigue Wizard leads you through the steps necessary to perform complex fatigue life calculation. You can view results as life or safety factors using the Fatigue Wizard post processor, or export and view in Autodesk® Simulation Mechanical. With minimum effort and time, you can use Fatigue Wizard to generate customizable reports.

To Launch Fatigue Wizard

Launch Fatigue Wizard from the Fatigue Analysis command that appears in the Simulation Mechanical ribbon. The command is located within the Analysis panel of the Analysis tab and appears in both the FEA Editor and the Results environments.

Note: For large models or those with many load cases or time steps, it may take 30 seconds or more for files to be prepared and data transfer to Fatigue Wizard to begin. During that time, it may appear as if nothing is happening, but a progress bar will eventually appear. Please do not click the command more than once.

Note: When a fatigue analysis has been completed, you may need to close the Results environment window in Simulation Mechanical and reopen it. This causes the available results to be re-read so that the newly-created fatigue analysis results are available for selection and display.

Supported Analysis and Element Types

Fatigue Wizard supports the results from the following three Simulation Mechanical analysis types:

• Static Stress with Linear Material Models
• Mechanical Event Simulation (MES)
• Static Stess with Nonlinear Material Models

Only solid elements are supported, including:

• Element Type = Brick (all variants of the hybrid brick element are supported (4-node tetrahedra, 5-node pyramids, 6-node wedges, and 8-node bricks - with and without midside nodes).
• Element Type = Tetrahedron (but only for linear static analyses and only if midside nodes are included)

Important: Do not attempt to run a fatigue analysis when the FEA Element Type is Tetrahedron and midside nodes have not been enabled within the Element Definition dialog box. Also, do not attempt to run a fatigue analysis from a nonlinear structural simulation when the Element Type is Tetrahedron, whether or not midside nodes are included. In either case, the fatigue analysis will terminate with an error message.

Fatigue Wizard Features

Fully Functioning (SN and EN)

Fatigue Wizard can perform sophisticated fatigue life analyses, from conventional stress-based (SN) analyses to low cycle strain-based (EN) analyses with plasticity correction. Mean stress corrections can be accounted for using standard methods. Endurance modifiers such as surface finish, temperature, and so on, are all available. For a complete list of the capabilities within the Fatigue Wizard, follow the features link.

Multiple Load Cases (Non-Proportional)

Fatigue Wizard can perform fatigue calculations using stress results from multiple load cases. Results from multiple load cases can be scaled individually using separate load histories of up to 30000 points, and analyzed as a combined load case. Alternatively, stress states from individual load cases can be used in sequence to produce the cyclic stress history.

You can scale each load case and load history individually to determine the sensitivity of fatigue life to load case.

Material Database

Successful fatigue analysis depends entirely on accurate material data. Fatigue Wizard ships with an extensive material database for stress life curves (SN) and strain life curves (EN), and component data for welded joints to BS7608. You can add to the database as data becomes available.

Fatigue Wizard also includes the capability to estimate strain life material data from readily available mechanical properties, using standard empirical relationships.

Post Processing

Fatigue Wizard includes post processing tools. An OpenGL results post processor is included within the wizard interface. You can view life contours or safety factor contours before you step back to perform 'what-if' analyses.

Fatigue Wizard also includes an automated report writer. You can create and export summary reports of the analyses you perform. This feature maximizes the time available for analysis.

Analysis Options

Fatigue Wizard additional 'advanced' forms. With analysis options, you can control the mean stress corrections and FEA stresses to use. You can control the portion of the FEA model to analyze, based on a ranked maximum stress range. Yo can also exclude parts from the fatigue analysis.

You can perform fatigue calculations using equivalent stresses, such as signed Von Mises, tresca, and maximum absolute principal stress. Alternatively, a critical plane approach is implemented using resolved surface normal or shear stress.

Analysis Speed

Fatigue Wizard offers several choices to aid speed of calculation. You can select the choices individually depending upon the required speed, reliability, and desired output. You can analyze all of the model, or parts of the model. You can analyze the model selectively based on your defined 'groups,' or by a given percentage of nodes based on a ranked nodal maximum stress range.