Tuesday, September 29, 2015

Defining and Generating a FEA Mesh - FEA Practical applications and tutorials

In general , the basic platform and tools for Meshing task is common in all FEA pre-processing softwares like NX Nastran, Hypermesh,Cosmol, Abaqus, Ansys etc. This article will give a brief overview of the basic of mesh generation technique in FEA.

Defining and Generating a Mesh

The Meshing task will provide tools to help us to define and generate a FE mesh. We can
  • use the geometry checking tools to verify that your geometry is ready for meshing
  • define parameters for the mesh
  • preview the mesh before you generate nodes and elements
  • generate the mesh based on the mesh parameters
  • check the quality of the mesh
  • update the mesh after solution
  • modify individual nodes and elements as necessary

Defining a Mesh

When we define a mesh, we should specify parameters such as:
  • mesh type. Mesh generation can produce either regularly-spaced finite elements (mapped mesh) or less restrictive free elements (free mesh).
  • element type and length
  • elements' physical and material properties
  • We can always choose default or previously-defined settings when you create a mesh. Often, however, you will want to control the meshing process more by changing some of the default parameters

Meshing Limitations

We can't mesh adjacent entities with a different element order defined. For example, we cannot define a linear element type (say four node element) for a mesh on one surface (x) and then define a parabolic element type ( say eight node element) for an adjacent surface (y). This creates a mismatched element order where the surfaces join (z).

We can't mesh adjacent entities that have a free and a mapped mesh defined on them.