Material

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Revision as of 14:49, 1 February 2013 by Jriegel (talk | contribs) (→‎Rules)

This page is about the material data system in FreeCAD.

Abstract

Since its hard, or even impossible, to define a fixed or complete set of material properties, we go a more open way. Every object in FreeCAD which has to deal with material will have a Property named "Material" which is in itself a key/value list which can hold a infinite number of material properties. Since this is a very open and extensible way to deal with such data, its hold also the danger of chaos. There fore this page define some rules and basic properties to deal with such material-property-maps.

Rules

Every property set has only one mendatory entry which is "Name". This is the primary key of the material. The rest of the matrial properties are optional or can be retrived out of a material DB.

Property names (key) are ordered by strings separated by underscores. The first substring is named by the application or standard, the following can be used to further group the properties. Examples:

  • EN10027_name = S235JR+AR (steel standard EN 10027-1)
  • FEM_YoungsModulus = xx ( in mm−1·kg·s−2
  • FEM_YoungsModulus_Z
  • FEM_YoungsModulus_X

Each property has a human readably description on this Material page, with links to further information (e.g. Wikipedia).

For each property a unit has to be defined, based on the FreeCAD internal unit mm-kg-s! That allows consistand usage and translation.

The underscores allow later a tree view property editor/viewer which allow folding.

Material Database

Basic material properties

General

Mechanical

Finite Element Method

Computational Fluid Dynamics