How to Generate Solid Meshes for Thin Cross-Sections

Figure 1: Activating the "Use Thin Cross-Section Scheme" Option

If you are preparing to generate a solid mesh using brick elements and the part is thin (i.e., if a mesh that is fine enough to consist of three or more bricks through the thickness would cause a prohibitively large analysis based on computer system resources or analysis run time), consider using the thin cross-section option. This control, which can be accessed in Superdraw or the CAD Solid Model environment, is designed to create better quality elements in thin parts.

After a surface mesh is placed on the part with one or two elements across the thickness, in Superdraw, use the "FEA Mesh:Solid Mesh Generation..." command sequence or, in the CAD Solid Model environment, use "Mesh:Solid Mesh Generation...". The "Solid Mesh Engines" screen will appear.

Click on the "Options..." button to access the "Solid Mesh Options" screen. Click on the "General Controls" tab. Under "General", click on "Use Thin Cross-Section Scheme". A checkmark will appear in the box to the left indicating this option is active. (See Figure 1.)

Using the thin cross-section option, the solid mesh engine will examine nodes on the top, bottom and side surfaces of the part and attempt to align matching nodes on two opposite surfaces of the mesh. It may change one side of the surface mesh so that it aligns with the other side of the surface mesh. This enables it to create more uniform elements through the thickness (typically, one or two brick elements through the thickness).

Note: You can use the "Do Not Change Surface Mesh of Layer Number" option to specify which sections of the surface mesh cannot be altered during solid meshing. This is helpful in conjunction with the "Use Thin Cross-Section Scheme" option for when you do not want one side of the surface mesh to be changed; you can ensure that it will be the other side that will be changed if need be. For example, if one side of a thin part is matched to another part of an assembly during surface mesh matching, then the lines of the surface will be changed to layer 14, which indicates feature lines. If you enter "14" in the "Do Not Change Surface Mesh of Layer Number" field, then this surface will be preserved during solid meshing.

For more information about solid meshing thin cross-section parts, see the ALGOR User's Guide.