The options in the Mesh Refinement sub-menu of the Mesh menu, provide the user with some very powerful options for customizing the finite element mesh, after the mesh has been generated. These include:
Increasing the density of the mesh in any area with the Increase Density option
Creating a regular (mapped) mesh in any closed region bounded by 3 segments (Mapped Triangular Region) or 4 segments (Mapped Rectangular Region). See the Mapped Meshing topic for a discussion of these options.
Troubleshooting mesh problems with the Show Mesh Quality and Define Mesh Quality options. See the Mesh Quality topic for a discussion of these options.
Remember that these options require that the finite element mesh has already been generated, with the Generate Mesh option (or the Discretize and Mesh option).
The Increase Density option allows the user to select any area of the mesh within a rectangular window, to increase the density of the mesh within the window. To use this option:
Select Increase Density from the Mesh Refinement sub-menu of the Mesh menu.
Use the mouse (or the keyboard) to enter two points defining opposite corners of a rectangular region, in which you would like to increase the mesh density.
After the second corner of the window has been entered, the density of the mesh within the selected region will be automatically increased, according to the following rules:
A new node is automatically inserted at the center of each finite element, within the selected region.
A new mesh is then generated, which uses ALL OF THE ORIGINAL nodes which existed, as well as the new nodes inserted at the element centers within the selected region.
If the results of using Increase Density are unsatisfactory, remember that you can always use the Undo option to Undo any actions in Slide, or you can use Increase Density any number of times, until the mesh is sufficiently refined.
NOTE: the discretization of the model boundaries is NOT affected by the Increase Density option. Only the mesh density within the boundaries is affected. If you need to increase or modify the density of nodes on the boundaries, you can do this BEFORE the mesh is generated, using the options in Mesh Setup, or with the Custom Discretize option. You can also refine the boundary discretization, BEFORE or AFTER the mesh is generated, with the Double Discretizations option.