A section is a cut in the structure where forces and moments will be computed and stored
in output files.
It is defined by:
A cutting plane
A reference point to compute forces
A direction of the section.
Figure 1. Definition of a Section for an Oriented Solid
In Radioss the cutting plane is defined by a group of elements and
its orientation by a group of nodes as shown in Figure 2.Figure 2. Definition of a Section for a Shell Mesh
Then, a point is defined for the center of rotation of the section and a reference frame is
attached to this point to compute the internal efforts.Figure 3. Center of Rotation and its Associated Frame for a Section
The resultant of all forces applied to the elements and its application point are computed
by:
Figure 4. Resultant of Force and Moment for a Node I with the Rotation Point O
