The Finite Element Mesh is the
collection of Nodes and Elements used to represent the system in order to
transform the continuous mechanical problem into a discrete numerical
problem. All user specifications on the system geometry are eventually
translated by the program into Mesh input data.
The important element characteristics are their order, their size
and their sag. The order is the degree of polynomial interpolation
for the unknown field (the displacement field) inside the element, the
size is the dimension of the element and the sag is a measure of how
closely the element boundaries follow the geometry they are supposed to
represent.
At constant element order, a finer mesh is expected to produce better
results than a coarse mesh, but at a higher cost (more Memory and Time
required to generate the results). Likewise, at constant mesh size, a
higher-order elements mesh is expected to produce better results than a
lower-order elements mesh. This is also true locally: results are more
precise in a region of high order and low size elements.
