# Geometric Tube: section

## Rectangular section

A rectangular section is defined by:

• a width
• a height
• an orientation

## Variously-shaped section

A variously-shaped (full or hollow) section is defined by:

• a profile
• a layer thickness (only for hollow sections)
• a orientation

## Profile

A profile is composed of a series of segments having not necessarily right angles between them.

In the case of a full section, the profile represents the contour line of this section; in the case of a hollow section it is its center line.

A profile is defined by:

• a type: closed or open

an open profile will necessarily have to be associated to a hollow section

• a origin (or center) of a local 2D coordinate system; this point is the point to which the tube points are connected during the geometric tube creation
• coordinates of points to build the segments defining the profile in the local coordinate system

if a profile is closed, the Flux PEEC software automatically adds the segment to connect the last point of the list to the first one.

Examples of profile and section are shown in the figures below; the red points represent the Tube Points.

full section – closed profile

hollow section – closed profile

hollow section – open profile

## Orientation (1)

For a Geometric Tube formed of a single Tube Line (or a set of aligned Tube Lines), the orientation of the section is defined by the user using an angle of rotation.

An example of a rectangular section is presented in the figure below.

## Orientation (2)

The orientation is imposed by Flux PEEC for a Geometric Tube formed by a set of nonaligned Tube Lines. The orientation of a section depends on the shape of Geometric Tube, i.e. of its Tube Points positioning, as well as the profile shape.

The user can define a rotation angle of 90° (or its multiples) to make turn the rectangular section of 90°. That is equivalent to swap the height and width values for a rectangular section.

In the example below the rectangular section is oriented using the rotation angle.

Rotation angle = 0° Rotation angle = 90°