FEA Editor Environment

Use the FEA Editor environment to define the analysis.

You can define properties for multiple parts simultaneously. Select the items to define (Element Type, Element Definition, Material) in the tree view and right-click for the menu of options. Or, select the parts in the display area, right-click, choose Edit and then the property to set.

Miscellaneous Functions (Visibility, Suppress, Copy and Paste)

When a part or surface is selected and you right-click, the context-sensitive pop-up has numerous options for working with the selection. This section describes some of those options.

  • Visibility and Suppress: A hidden part or surface is removed from the display area but not from the analysis to make it easier to work on some sections of the model without the clutter of the hidden parts. Suppressed parts are removed from the display area and from the analysis. The icon in the tree view distinguishes between the different settings.
Icon Status of Part or Surface
Part is activated and shown (not suppressed, visibility activated)
Part is selected (while activated and visible)
Part is hidden (visibility deactivated)
* Part is suppressed. *Note that the part name is also rendered using a gray strikethrough font.
Surface is shown (visibility activated)
Surface is selected (while visible)
Surface is hidden (visibility deactivated)
  • Edit: When a part is selected, the Edit command is available. In addition to setting the Element Type, Element Definition, and Material properties, the color of the part can be changed.
  • Copy and Paste: When a single part is selected, the properties of the part can be copied to the clipboard. When a different part or multiple parts are selected, those properties can be pasted to the new part. The properties that can be copied from one part to another are the color, description, element type, element data, material properties, or all these attributes.
    Note: Properties set as a design optimization design variable are not pasted to the Element Definition. These need to be set individually.
  • Save/Read Part Attributes: When one or more parts are selected, the commands Save Part Attributes to File and Read Part Attributes from File are available. These two commands are like the Copy and Paste functionality. The main difference is that the Save command saves the data to a file, not to the clipboard. Thus, the data can be read into a different model by using the Read command. (The Paste command only works in the current model; the clipboard is cleared if a new model is started or opened.)

    When the Save command is used, a Browse For Folder dialog box is presented. Choose where to save the files and click the OK button. The name of the file is automatically set as follows: <FEM File Name>_<Design Scenario>_<Part Number (Part Name)>.apif where <FEM File Name> is the name of the model, <Design Scenario> is the design scenario number, and <Part Number (Part Name)> is the number and name of the part with the name enclosed in parentheses (). All attributes of the part (color, description, element type, element definition, and material data) are saved.

    When the Read command is used, a standard Windows Open dialog box is presented. Select one or more apif files to read and click the Open button. Then, the Select Attributes to Apply dialog box appears. Choose which items to read from the files and apply to the selected parts. The multiple selection capability behaves as follows:

    • If a single apif file is selected, the chosen attributes in the file are transferred to the selected parts without considering the part number. For example, saved attributes from part 2 can be applied simultaneously to parts 3, 10, and 15 in a new model.
    • If multiple apif files are selected, the attributes in the files are transferred to the selected parts only when the part numbers are identical. For example, the attributes for parts 1, 2, and 3 in model A are saved. Parts 2, 3, and 4 in model B are selected when the Read command is used. Since part 1 is not selected in model B, the part 1 apif file is ignored. The attributes for parts 2 and 3 are updated because the files chosen and the parts selected match. Since no apif file was selected for part 4, its attributes are not changed.
      Note: The Read command compares the units stored in the apif file with the model units of the current model. If they are different, the Read command does not proceed. The units must be the same in apif file and current model.

Select Element Types

The first step in setting up a structural analysis is to select the element type for each part in the model. In some cases, the element type may already be defined.

  • If the part was solid meshed in the FEA Editor environment, the element type will already be defined as brick elements.
  • If a part was midplane meshed in the FEA Editor environment, the element type will already be defined as plate elements.

If the mesh was not generated by one of the preceding methods, a red X will appear on the Element Type heading in the tree view for that part. You can select the element type for that part by right-clicking on the Element Type heading and selecting the appropriate command from the resulting menu. Note: The 2D command will only appear in the menu if none of the parts in the model contain nodes that are not in the YZ plane at X=0.

Define Element Parameters

Once the element type is defined, you must define the parameters for each part. This is done by right-clicking the Element Definition heading for the part in the tree view and selecting the Edit Element Definition command. It accesses the Element Definition dialog box.

Default values are set for some element types, so visiting the Element Definition screen is not necessary. You can make changes to the defaults for the particular application.

Define Material Properties

Once the Material headings for the parts are selected, right-click of the selected headings and select the Edit Material command. The Element Material Selection dialog box will appear.

The first step is to choose a material library from which to retrieve information. The default library is the Autodesk Simulation Material Library unless a different default is set in the Material Library Manager (see the paragraph How to Set a Default Library: on the page Setting Up and Performing the Analysis: Material Library Manager: Customizing a Material Library). (If the part already has a material assigned to it, the library from which the material was chosen is shown.) If you have added materials to another library, you can select the other libraries in the Select Library drop-down menu. The materials in the selected library that match the material model specified in the Element Definition is shown in the list. Selecting a material from the list will display the properties in the grid on the right side of the dialog box.

Conversions from different unit systems are done by the software. If you entered a material in English (in) units in the material library, you can still retrieve this material if you use a different unit than English (in).

The Current Material Information section in the grid will describe the data of the material previously assigned to the part (before choosing a new material). This data includes the following:

  • Analysis Type: The general category for the analysis.
  • Element Type: The element type specified for the part.
  • Material Model: The library equivalent of the material model specified for the part.
  • Material Specified: This is the original material that was selected, before choosing a new material.
  • Material Source: The source or file from which the original material was selected.

The lower portions Material Identification and Material Properties are for the new material selected from the library and includes the following:

  • In Library File: Library where material is located.
  • Date Last Updated: The last date the material was changed in the library or model.
  • Unit System: The unit system that the material was entered in. Remember, the software will convert the units for you.
  • Material Description: The description of the material from the library.
  • Source: The book or web site from which the material data was retrieved.
  • Selected Material: The name of the material selected from the library. The name is also shown in the grid's title bar and in the tree view.
  • Material Properties: The appropriate material properties that are needed in the analysis. The library may contain additional input which is not required for the analysis. For example, heat transfer properties (conduction, specific heat) can be entered in the material library, but they are not shown during a structural analysis because they are not relevant.

To view the material properties of a material, select the material; the properties are displayed in the grid on the right-hand side. For tabular and other specialized properties that do not conveniently fit in the grid, press the Edit Properties button. This will bring up the material specification dialog box for that material and material model.

Changes can be made to a selected material by pressing the Edit Properties button. The Edit Properties will move you into the material specification dialog box. (Some properties and functions are only available from the Edit Properties dialog boxes.) If you make any changes to the material, the name of the material will change to [Customer Defined]. These changes are saved to the model database if the OK button is pressed but will not be changed or saved in the material library. If a material is going to be used many times, it is suggested that you save the material properties in your own material library as follows:

  1. If a custom library does not already exist, use the Create New Library button to create one.
  2. Use the Select Library pull-down to choose a library in which to save the [Customer Defined] material. The library Favorites exists for all users. Also, the Autodesk Simulation Material Library is locked, so custom materials cannot be added to it.
  3. Right-click the [Customer Defined] entry at the top of the library and choose Save to Library. The Save Material to Library dialog box will appear.
  4. Enter a name for the material and select a category (folder) in which to save the material.
  5. Click the OK button. This will add the material to the library and return to the Element Material Selection dialog box.
  6. Click the OK button to apply the material to the model.

See also Setting Up and Performing the Analysis: Material Library Manager.

Apply Loads and Constraints

Unless otherwise noted, loads and constraints can be added to the model following these steps.

  1. Make sure that you are in the correct selection mode to apply the type of load or constraint that you are interested in. For example, if you are going to apply a nodal force, you must be in nodal selection mode (SelectionSelectVertices).
  2. Select the objects that you want to add a load or constraint to using any of the selection methods (point, circle, rectangle and so on).
  3. Right-click in the display area.
  4. In the resulting pop-up menu, select the Add pull-out menu.
  5. The resulting pull out menu will vary on the type of analysis you are performing. Click the type of load or constraint that you want to add.

Whether the applied load is on a part, surface, line, edge, or node (vertex) can be determined from the title in the Load and Constraint Group (see the Group Loads and Constraints section) or by the color of the symbol shown on the model. The following colors are used:

Type of Load

Color of Symbol

Nodal

Red or Blue

Edge

Gold or Green

Line

Brown

Surface

Olive or Yellow

Part

Orange or Purple

Specify Directions of Loads

Many loads are applied along a specific direction. This direction can be specified using three methods. The dialog boxes for these loads will contain a Direction section. This section will contain X,Y and Z radio buttons. If the load is applied along one of these axes, select the appropriate radio button. If the load will not be applied along one of these axes, select the Custom radio button. Now you can either specify the vector using the X, Y and Z fields or you can press the Vector Selector button. Pressing the Vector Selector button will take you to the display area. You can define the vector by clicking on two nodes in the model. When you are over a node, the cursor will turn to a padlock icon. Clicking at this time will select that node. Once you select two nodes, you will return to the dialog box and the vector is set in the X, Y and Z fields.

Note: The directions are components of a vector which are normalized to 1 during the analysis. They are not multipliers for the load magnitude. For example, 10 N with a direction of [1,1,0] gives 10 N total: 7.071 N in the X direction and 7.071 N in the Y direction. It does not result in 10 N in the X and 10 N in the Y.

If the nodes to which you are applying nodal loads or constraints are using a cylindrical reference frame, the X, Y and Z values refer to the R, ϑ, and Z directions. If the nodes to which you are applying nodal loads or constraints are using a spherical reference frame, the X, Y and Z values refer to the R, ϑ, and φ directions.

Group Loads and Constraints

When a load or constraint is added to the model, an entry is created in the tree view under the branch labeled as Load and Constraint Groups. Use the Groups to place similar loads and constraints together for ease of working on all objects within the Group. For example, by selecting the heading of the Group, all items can be shown or hidden, modified (if they are the same type of item), and disabled.

As another example, some loads are assigned to a load case (Static Stress with Linear Material Models) or load curve (Mechanical Event Simulation) when they are applied to the model. Nodal forces are an example. If similar forces are at the same nodes (or closely spaced nodes) but in different load cases/load curves, it may be convenient to place all loads on load case/curve 1 into one Group and place all loads on load case/curve 2 into a different Group. When working on the model, the loads in one Group (load case) can be hidden to better visualize what is on another Group (load case).

Note: Other than enabling and disabling the Group, which Group an item is assigned to has no affect on the analysis. The load case or load curve number to which a load is assigned has no correlation with the Load and Constraint Group number.

Assign Loads/Constraints to a Group

By default, a new load or constraint added to the model is placed in a new Load and Constraint Group. Once a Group is created, new loads or constraints can be added by one of these methods:

  • Before applying the load/constraint, right-click the Group heading and choose Set Active. The Group is shown in bold to indicate that it is the active Group. New loads/constraints are placed in the active Group.
  • After applying the load/constraint, the individual items can be selected in the tree view and dragged (with the left mouse button) and dropped to an existing Group.
  • Or instead of dragging the load/constraint, select the individual items, right-click, and choose Move to Group. The Move FEA Objects to Group dialog box lists the available Groups and give an option to move the item to a new Group.
  • If you want loads and constraints from several Groups moved to a single Group, select the Group headings, right-click, and choose Merge.

Include or Not Include a Group in the Analysis

All loads and constraints in an Group can be removed from the analysis by disabling the Group. To disable the Group, right-click the Group's heading and check Suppress. To enable the Group and return the items to the analysis, select the heading, right-click, and uncheck Suppress.

Note: Items in the Group are still visible when they are disabled. Clear the Visibility option, when you right-click the Group's heading, to remove them from the display. Hidden items are still included in the analysis; only the Suppress status affects whether they are included or not. Select the Visibility option to display the items in the Group.

Change Items in a Group

By selecting the Group heading in the tree view, the items contained in the Group can be modified as follows. Recall that the <Ctrl> and <Shift> keys can be used to select multiple Group headings simultaneously.

  • Right-click and choose Delete to delete all loads and/or constraints in the selected Groups.
  • Right-click and choose Edit to edit all the loads or constraints in the selected Groups. However, the Edit command is only available if all the items contained in the selected Groups are the same type of item.

Define Analyses Parameters

Once the analysis type is defined, you can define the analysis parameters. This is done by right-clicking on the Analysis Type heading in the tree view and selecting the Edit Analysis Parameters command. Depending on the analysis type, the default values may be adequate and you are not required to access this dialog box.

Parent topic: General Information (Common to Multiple Analysis Types)