CAD-CAE Integration — CAE Glossary

That often doesn't work out. CAD models contain huge amounts of tiny features added by designers for appearance—micro fillets, logo engravings, detailed screw threads. When you try to mesh these directly, either the element count becomes astronomical or the mesh generation fails entirely.

For something like an engine bracket, raw CAD data might result in 10 million elements, but with proper defeaturing, 500,000 elements gives equivalent accuracy. That's a 20x computation time reduction. In practice, this CAD-to-CAE data transfer step is critical to overall analysis efficiency.

Technically their roles differ. Geometry cleanup fixes "defects" in CAD data. For example, gaps between surfaces, duplicate surfaces, tiny edges, and free edges—correcting these makes the solid watertight so meshing is possible.

Defeaturing is intentionally removing minor features that don't affect analysis results—even though the geometry isn't broken. Specifically:

Yes. Ansys SpaceCllaim, SimLab, HyperMesh's Geometry Cleanup, and CATIA V5's Part Design Simplification have automated features. They can do things like "remove all fillets below this size." But they're not 100% automatic—humans still need to do final verification based on analysis objectives. In the field, people say "30% of analysis time goes to cleanup"—it's unglamorous but crucial work.

Both are neutral formats for exchanging data between CAD systems, but they're different generations.

Parasolid (.x_t / .x_b) is the native format of Siemens' geometry kernel. SolidWorks, NX, and Solid Edge all use Parasolid internally, so exchanging Parasolid files between these CADs loses the least information. CAE software like Ansys and Abaqus also have Parasolid readers. Among CADs sharing the same kernel, Parasolid often causes fewer troubles than STEP.

The most common issue is tolerance mismatch. If CAD software A defines surface-to-surface joints at 0.001mm tolerance but CAD software B reads it at 0.01mm tolerance, tiny gaps get flagged as "gaps exist" and the solid collapses. Always set "high precision" when exporting STEP files, and run geometry checks (detecting free edges and non-manifold vertices) after import.

Yes. Direct CAD interface allows reading CAD's native format directly into CAE software without intermediate files. For example, Ansys Workbench can open CATIA .CATPart or SolidWorks .sldprt directly. Abaqus/CAE has "CAD Connection" for CATIA V5 and SolidWorks, and HyperMesh has a native CAD reader too.

Significantly reduces them. The big advantage is avoiding geometry loss and tolerance inconsistencies from intermediate conversion. You also get "associative linking"—design changes in CAD automatically update the CAE model. For instance, if a designer changes flange thickness, the analysis model's geometry and mesh update automatically. That's powerful for design optimization loops.

Not quite. Direct interfaces are version-dependent—CAD updates can break compatibility until CAE software updates. And suppliers send external data in their CAD format, which you can't read natively. In practice, people use "direct interfaces internally, STEP for external data." That's the standard split.

Here are the critical points from practice:

Ansys SpaceCllaim and HyperMesh have automatic midsurface extraction. They work well on uniform thickness sections, but variable thickness areas and rib intersections usually need manual fixes. Industry wisdom: "80% automatic, 20% manual." That last 20% eats time, which is why "CAE-aware design"—making shapes analysis-friendly from the start—is gaining traction.