Geometry building process

Outline

An outline of the geometry building process is presented in the table below. The different steps are detailed in the following blocks.

Step	Description
1	Device analysis
2	Definition of the study domain
3	Preparation of the geometric construction tools
4	Ascending construction of the geometry
5	Regrouping in regions

Device analysis (1)

The first step of the geometry building process is the device analysis :

to define the study domain, and
to prepare the geometric description

The questions that could arise at this level, before starting the description itself, are grouped in the tables below (non exhaustive list).

Analysis to:	Device features
define the study domain	Does the device have geometric and/or physical symmetries or periodicities? Can it be studied using the infinite box feature or should we limit the study domain in a different way?

Analysis to:	Device features
prepare the geometric description	Can the device be simplified without consequences on the study physics: approximation of complex shapes, removal of rounded corners, chamfered edges, holes…? Does it have moving parts, variable thickness, repetitive patterns…?

Analysis to:	Is it necessary
prepare the mesh	to add points, lines, or faces in order to make easy the mesh building (skin depth…)?

Analysis to:	Device features
prepare the physical description	Does the device have specific shapes (such as thin bars, air gaps or magnetic armatures…) that can be replaced by points, lines or faces (considered as point, line or surface regions)?

Next steps (2, 3, 4, 5)

The other steps of the geometry building process are described in the table below.

Step of …	The user
Step of …	creates…	builds…	assigns…
Defining the study domain (2)	the symmetries the periodicities the infinite box
Preparing the geometric building tools (3)	the geometric parameters the local coordinate systems the transformations
Ascending construction of the geometry (4)	the points the lines	the faces the volumes
Regrouping in regions (5)	the point regions the line regions the face regions the volume regions		the regions to points, lines, faces, volumes respectively

Operations order

The different steps were presented in a “chronological” building order.

In practice, the geometry building process is not always linear and the user proceeds by successive steps. In this case, he makes “go and return” between different steps.