Background on Meshing
Finite
Element Analysis (FEA) provides a reliable numerical technique for analyzing
engineering designs. The process starts with the creation of a geometric
model. Then, the program subdivides the model into small pieces of simple
shapes (elements) connected at common points (nodes). Finite element analysis
programs look at the model as a network of discrete interconnected elements.
The Finite Element Method (FEM) predicts
the behavior of the model by combining the information obtained from all
elements making up the model.
Meshing is a very crucial step in design
analysis. The automatic mesher in the software generates a mesh based
on a global element size, tolerance, and local mesh control specifications.
Mesh control lets you specify different sizes of elements for components,
faces, edges, and vertices.
The software estimates a global element
size for the model taking into consideration its volume, surface area,
and other geometric details. The size of the generated mesh (number of
nodes and elements) depends on the geometry and dimensions of the model,
element size, mesh tolerance, mesh control, and contact specifications.
In the early stages of design analysis where approximate results may suffice,
you can specify a larger element size for a faster solution. For a more
accurate solution, a smaller element size may be required.
Meshing generates 3D tetrahedral solid
elements, 2D triangular shell elements, and 1D beam elements. A mesh consists
of one type of elements unless the mixed mesh type is specified. Solid
elements are naturally suitable for bulky models. Shell elements are naturally
suitable for modeling thin parts (sheet metals), and beams and trusses
are suitable for modeling structural members.
This section discusses the following topics: