ABAQUS/CAE decides that mapped meshing is appropriate in a four-sided region when:
it is likely that the mesh quality will improve, and
any minor adjustments to the mesh seeding will not violate the user's intent (as indicated by any existing seed constraints).
When ABAQUS/CAE applies mapped meshing, it makes small adjustments to the mesh seeding to ensure that opposite sides of the rectangular region have the same number of seeds. If your model is large and includes many simple regions, it can be very time consuming for ABAQUS/CAE to check for rectangular regions and adjust the seeds. Therefore, meshing the model may be significantly slower if you allow ABAQUS/CAE to apply mapped meshing where appropriate.
Figure 17–64 shows a shell part meshed with triangles using the following mesh techniques and algorithms available in ABAQUS/CAE:
Free meshing
Free meshing using mapped meshing where appropriate
Structured meshing
In many cases a free mesh of triangles with mapped meshing where appropriate will be the same as a structured mesh of triangles. The meshes are different in Figure 17–64 because ABAQUS/CAE honors the original seeding and determines that mapped meshing is not appropriate on the side of the part. In contrast, when ABAQUS/CAE creates the structured mesh, it adjusts the seeding to create the structured mesh that was requested by the user.
