Some of the more common reasons why a region fails to mesh and the associated solutions are as follows:
- Inadequate seeding
The region contains some small edges or the seed density is too coarse. You can use the Virtual Topology toolset to merge small edges. Alternatively, if you save the region that failed to mesh in a set, you can apply local seeds of a finer density to the saved set.
When you are creating a hexahedral mesh, a quadrilateral mesh, or a quadrilateral-dominated mesh using the medial axis algorithm, Abaqus may need to alter seeds to generate the mesh. In some cases, mesh generation may fail because the modified seeds density is too coarse. Meshing may succeed if you incrementally mesh the regions of the part in a different order, or, as described above, you can apply local seeds of a finer density and remesh the part.
- Bad geometry
Bad geometry refers to small edges or faces or to part instances that are imprecise. You can use the Query toolset to check the geometry. For more information, see Using the geometry diagnostic tools.
- Poor boundary triangles
When you are creating a free mesh with tetrahedral elements, Abaqus/CAE first creates a triangular mesh on the faces of the region and then uses those triangles as faces of the boundary tetrahedral elements. You can choose to preview the triangular mesh on the faces and decide if it is acceptable before continuing with the time-consuming process of generating tetrahedral elements through the interior of the region. For more information, see What is a tetrahedral boundary mesh?.
In some cases Abaqus/CAE cannot complete the conversion from triangles to tetrahedra and highlights the nodes on the boundary mesh that cannot be inserted into the tetrahedral mesh. The highlighted nodes serve as indicators of regions that require attention, and you can try the following:
Use the seeding tools to increase the mesh density.
Use the Virtual Topology toolset to combine small faces and edges with adjacent faces and edges.
Use the Partition toolset to partition regions into simpler subregions.
Use the Edit Mesh toolset to improve the tetrahedral boundary mesh.
Use mesh controls to change the mesh technique applied to faces of the solid region.
- Gasket regions
You can generate a gasket reinforcement mesh only on a region that contains a gasket mesh.