Geometry Import Guidelines

Workflow tips for geometry import in SimSolid.

SimSolid does not have a geometry engine, so when importing your model into SimSolid it is saved as faceted volumes and you can perform analysis on the boundaries created by these faceted volumes. How well the faceted volumes represent the overall geometry is controlled by the import options. SimSolid allows different levels of refinement.

SimSolid has preset options like Standard, Enhanced and Fine and a Custom option where you can manipulate angular and chordal deviations. Increasing the resolution is going to increase the number of facets and hence it's also going to increase the solution time. Fine or Custom settings may not be best practice for all cases. Choose your import settings wisely based on the geometry that you're working with and the objective of your analysis.

For example, if your end goal is to perform stress analysis, you may want to avoid rough facets that can introduce stress concentrations. In such cases, go with Enhanced or Fine settings. But if your objective is to look for stiffness, you can get away with standard import settings in most of the cases.

  1. Use Parasolid reader for best results.
    1. This reader only brings in solid geometries ignoring other data.
    2. Parasolid files is preferred over step files.
    3. With NX, use native geometry files.
    4. With CATIA, 3dxml files are lighter and faster to import.

    Figure 1. Settings > Geometry import settings
  2. Be cautious using the legacy reader.
    1. Access legacy reader by unchecking ‘use Parasolid reader’ option from geometry import settings.
    2. Legacy reader would repair the geometry during import.
    3. It works well if there are small gaps/overlaps in the geometry, can use HyperMesh/Inspire to check.
    4. Repair functionality can fail in other cases resulting in bad geometry.
  3. Always export geometry in assembly/global coordinates, so they are positioned correctly.
  4. If part instances exist, save a copy of the part that can be imported into SimSolid.