Use a Composite System (
) to define a coordinate system that acts as a consecutive application of two other coordinate systems. The base vectors of a composite coordinate system are defined as the base vectors of a selected
Relative system interpreted as relative to a selected
Base system, which may be
relative or
absolute. The resulting composite system is relative or absolute depending on the selected base system, which in the latter case also decides the underlying frame type.
In the Coordinate names table, the default names are entered —
x1,
x2, and
x3. In planar 2D models,
x1 and
x2 are typically the in-plane coordinates, and
x3 is the out-of-plane coordinate.
From the Base system list, choose a relative or absolute coordinate system that define a set of base vectors relative to an underlying frame. Then from the
Relative system list, choose a relative coordinate system whose base vectors will be interpreted as components in the selected Base system. Both the
Base system and the
Relative system can have the value
None, which is interpreted as an identity mapping of axes. Other
Composite System nodes are allowed provided that they do not cause a circular dependency.