In general, design analysis tools are demanding with respect to the geometric integrity. During the CAD modeling process these integrity requirements may not be met and may even go unnoticed. Examples of integrity errors include small gaps, overlaps, or overhangs which can easily be overlooked from the CAD point of view. However, they can be very troublesome for mesh creation.
Here are some general practices that may help with successful mesh creation:
Clean up or simplify the model in the modeling environment helps the simulation run more efficiently.
For example:
- For large assemblies, many of the parts may not play a role in simulation. Perhaps there are parts that do not carry significant loads and are not critical components in terms of structural or thermal integrity for the design. It's better to suppress those parts as it would simplify meshing and expedite the simulation process
- Parts that have very small features with respect to the overall model dimensions and do not play a substantial role in the simulation results can be suppressed. An example of small features would be:
- Very small holes, those with diameters less than 1/100 of the part length.
- Outer convex rounds with small radii.
- Label imprint and emboss features.
Suppressing such features can drastically simplify the meshing process and reduce the simulation time.
- Recreating or modifying some geometric features to remove hanging faces, very small edges, and so on, may, in some cases, help improve the quality of the geometry and therefore simplify the mesh generation process.
- In some cases the model is too complex and/or has geometric singularities. Divide the model into less complex parts that can be meshed independently and use a bonded contact between them to make these components behave as a single part.
- Some spring models mesh when the long helical face is split by a cutting plane containing the axis.
Use the appropriate meshing parameter values and settings to produce desired meshes.
- In some cases, due to complex curvature of a model, it is easier to generate a viable mesh by deactivating "Create Curved Mesh Elements." Use a finer mesh in the stress concentration area around a concave fillet or round to compensate for the lack of curvature.
- Use a finer mesh in troublesome areas that cannot be simplified. Decreasing the global mesh size, as well as the local mesh size on certain faces and edges, can help the creation of a successful mesh.
Note: This can increase the number of elements dramatically.
- For assemblies composed of many parts of different sizes, check the "Use part based measure for assembly mesh."