CAD Import Tab

Activate the command: Application Menu Options CAD Import tab, or Tools Options Application Options CAD Import tab.

CAD plugin options Section

The Loaded CAD and file translation plugins section will display all the available modules for loading CAD solid model geometry. If you select a plugin, you can press the About button for version information.

When some plugins are selected, the Options button becomes available. Click the Options button to set the default values used when importing or opening the CAD files. The options that you see depend upon the CAD program or universal CAD format selected. Some of the types of settings found in the CAD plugin options are:

• Specify whether to use the native CAD translator or Autodesk Inventor Server for CAD translation.
• Specify whether to import working points or datum points from the CAD model.
• Specify whether to import 3D sketches. This option is applicable to Autodesk Inventor models. 3D sketches are imported as wireframe geometry, suitable for line elements (for example, beams or trusses).
• Specify whether to import wireframe models or drawings as 2D objects. Additionally, there are options to translate 2D objects to a different plane upon importing. For example, 2D elements must be located on the YZ plane in Simulation Mechanical. However, 2D objects are typically drawn in the XY plane in CAD products. This option is applicable to AutoCAD *.dwg and *.dfx files as well as IGES wireframe files.
• Specify which part, surface, or layer number to assign to incoming objects when the part, surface, or layer identification (ID) in the CAD model is invalid.
• Specify whether to import separate blocks or bodies as separate parts or to merge multi-body parts into a single FEA part.
• Specify whether to import geometry as wireframes or 3D solid and surfaces. This option is applicable to AutoCAD *.dwg and *.dxf files.
• Specify an optional user-defined tolerance when translating the CAD data.

Tip: Many of the above options can also be accessed while opening a model using OpenOption within Simulation Mechanical.

Global CAD Import Options

The Global CAD Import Options button displays a dialog box where you can specify options to use when working with CAD solid models.

• Split surface on import: These radio buttons control when the surface splitting procedure is performed on CAD solid models. If splitting is performed, Simulation Mechanical reviews the geometry and attempts to match the areas where parts meet. This procedure benefits analyses involving contact and also helps you to generate additional parts based on the existing CAD geometry. Choose between the following three options:
  • Yes to always split the surfaces
  • No to never split the surfaces
  • Ask each time to decide whether to split or not each time a CAD model is imported.
  Note: If you do not initially split the model, but subsequently want it split, you must re-import the model. See the Surface Splitting page for details.
• The Automatically generate contact pairs option controls whether contact pairs are automatically detected and listed in the browser when importing a CAD model. If a large number of surface pairs need a contact type other than the default contact type, then activating this option may be beneficial. You only need to locate each appropriate contact pair in the list and change the contact type. For example, if one third of the surfaces will require bonded contact, another third will require free contact, and the remaining third will require surface contact, you could activate the automatic option before importing the model. Set the default contact type as bonded and redefine the other sets as free and surface contact, respectively. If a small number of contacting surfaces in your model require a different type of contact, then it may be advantageous to deactivate this option and generate the non-default contact pairs manually. Choose the option that results in the lesser amount of model setup work. See the Contact Pairs page for details. Choose between the following three options:
  • Yes to always generate the contact pairs automatically
  • No to never generate the contact pairs automatically
  • Ask each time to decide whether to generate the contact pairs automatically or not each time a CAD model is imported or reimported.

Options that you can separately define for the following two types of CAD model import operations:

• First time CAD import: These options only affect the treatment of newly created simulation models (that is, the first time a CAD model is opened or transferred into Simulation Mechanical).
• CAD reimport: These options only affect CAD models that are reimported into an existing Simulation Mechanical model. For example, revise a previously analyzed model in the CAD program to reduce the stress or displacement. Then, transfer the CAD model back into Simulation Mechanical to rerun the analysis. This workflow is a typical CAD reimport operation.

There are three parameters that can be defined separately for first-time and reimported CAD models, as follows:

• Import material data from CAD: This setting determines whether material properties (if any) specified in the CAD model are used for the Simulation Mechanical model. The choices are:
  • Yes: Import the material data from the CAD model.
  • No: Do not import the material data from the CAD model.
  • Ask each time: Decide when opening or importing each CAD model.
  Caution: Assume that you are reimporting a CAD model, and you previously edited the material properties in Simulation Mechanical. When the Yes option is chosen for this parameter, the Simulation Mechanical material properties are overwritten upon reimporting the CAD model. Also, be aware that you may have to define additional material properties within Simulation Mechanical, even when CAD material properties are available. For example, properties such as the plastic modulus or specific heat are often missing from CAD material libraries.
• Apply Simulation color scheme to CAD parts: This setting determines whether part colors (if any) specified in the CAD model are used for the parts in the Simulation Mechanical model. The choices are:
  • Yes: Use the standard Simulation Mechanical color palette, in which the colors are assigned according to the part number. For example, the colors of Parts 1 through 4 are green, red, yellow, and cyan, respectively.
  • No: Do not use the standard Simulation Mechanical color palette. Instead, use the part colors specified in the CAD model.
  • Ask each time: Decide when opening or importing each CAD model.
• Import part names from CAD: This setting determines whether part names specified in the CAD model are used for the Simulation Mechanical model. The choices are:
  • Yes: Import the part names from the CAD model.
  • No: Do not import the part names from the CAD model. Until you customize the part names in Simulation Mechanical, the parts are identified by number and are labeled <unnamed>.
  • Ask each time: Decide when opening or importing each CAD model.
  Caution: Assume that you are reimporting a CAD model, and you previously customized the part names in Simulation Mechanical. When the Yes option is chosen for this parameter, the Simulation Mechanical part names are overwritten upon reimporting the CAD model.