How to efficiently test modifications or refine a mesh without going back to the CAD and mesher step?
Industrial context: Why mesh-level interface handling is a key feature for model design optimization in vibration related challenges?
In design processes, entering simulation phase comes along with optimization. To achieve an optimal cost/performance ratio, many design variations must be tested, based on CAD revisions, material choices, etc…
Vibration related challenges often come during refinement phases, once a design baseline has been stabilized. This is a natural sequence of events often induced by the fact that design offices have limited access to realistic environment integration parameters and advanced simulation tools. NVH considerations thus arise during experimental prototyping.
Fine tuning vibration/damping optimization can be sensitive, best performed with a high number of design point evaluations. This enables parametric mode tracking or mode shape classification. As the baseline design parameters remain mostly constant, design modifications at the mesh level are critical for performance. This is why we develop local remeshing and morphing tools in SDT, enabling us to refine local connections, alter local topologies, or add dissipation devices such as viscoelastic patches.
Materializing new interfaces in a mesh is thus a key functionality whose features should include
- Local refinement strategy with mesh compatibility
- Insertion of physical lines or surfaces in a mesh
- Mesh dissociation along a given interface
These features are given here as a default sequence considering that the initial mesh was not prepared to consider an interface at the location of interest. Of course, any clever preliminary work at the CAD and/or initial meshing level could ease these steps!
I/ How to fine tune existing interface? Local refinement.
Interfaces, or detail additions in a mesh often require local refinement to integrate a smaller scale without generating too heavy models. SDT features several refinement strategies depending on the need. The most straightforward implementations are in feutil refine and feutil divide commands. These commands perform elementwise refinements and work best on structured meshes. For local refinements interface continuity is not always guaranteed but MPC-based interface connections are available.
To perform local refinement with mesh compatibility fe_shapeoptim refine commands implement groupwise strategies to ensure a compatible transition between the refined area and the base one.
Local hierarchical refinement in a sample plate, and an engine cradle shell mesh with local triangle inclusions.
This kind of refinement requires working on quadrangles for surfaces. Triangle inclusion for quadrangle dominant meshes are also handled. Mesh transformations can however be necessary when triangles or tetrahedra are dominant. 3:1 quadrangle refinement from triangles and the volume equivalent can be performed to recover quadrangles and hexahedra.
Triangle mesh conversion to quadrangle mesh, example of an automotive brake pad surface.
II/ How to efficiently introduce new interfaces? Insertion of physical lines at the mesh level.
Coming soon…
III/ How to model interface behavior? Mesh dissociation and interface layer.
Coming soon…