Pre-processing (Mesh Creation)#

Description#

The process of creating a model (FEA) in Zebulon is relatively straight forward. The following steps outline the general procedure. Note that the notion of a mesh is a separate entity from any specifics of the FEA model. Elements are only determined with respect to their geometrical form, and different portions of the geometry with different material properties, real constants, etc, are defined simply as groups of elements (elsets), nodes (nsets), or boundaries (bsets). Later, the specifics of the FEA solution are applied to these pure geometrical features.

Geometry and Mesh Creation#

The first step in the process is to define the geometry and place a surface mesh in it.

  1. Create geometry Use the tools described in the following pages (commands under GEOM) to create a boundary representation of the desired geometry, or import a geometry from another CAD program.

  2. Place nodes Nodes are to be placed on all relevant mesh boundaries (internal and external).

  3. Create domains Put domains in regions where a mesh is desired. Closed regions are created by selecting consecutive edges in the path in a counter clockwise sense. Internal boundaries for auto meshed regions can then be added by sequentially selecting a continuous closed loop of edges in a clockwise sense (inside the outer boundary of course).

  4. Save it’s generally a good time to save work before starting with meshing operations.

  5. Try meshing & Adjust Nodes some of the domains (esp with paving) may need adjustment of the edge nodes in order to get a good quality mesh.

  6. Create node Sets Interesting portions of the mesh boundary should have sets placed on them. Zmaster always creates both nsets and bsets with the same name for edge boundaries.

  7. Create 3D extensions: In Zmaster, 3D solid meshes are made by applying batch mesher extensions, sweeps, and transformations to the surface meshes.

Complex geometries are typically “built up” using several sub-meshes. These can be manipulated separately, and glued together with the union command (see the Mesher chapter).

  1. Create separate mesh components entailing the above steps.

  2. Create separate batch meshers manipulate the sub-meshes and seam them together as required.