Beam elements must be oriented properly with respect to the HyperSizer convention. Failure to do so leads to invalid results. The figure below shows the beam orientation convention for HyperSizer, Nastran, Abaqus, and ANSYS.
The beam normal is the HyperSizer z-axis. This vector can be viewed in the FEM viewer.
The beam material axis is the HyperSizer x-axis. This vector also can be viewed in the FEM viewer. The direction of this vector is usually determined by the ordering of the grids (A and B) in the element definition. It can be reversed to a FEM preprocessor.
Tip: Always verify beam orientations using the FEM viewer. See Show FEM Directions.
Stringer Segments - Beam Element Orientations
For beam elements belonging to stringer segments, the beam normal vectors (shown as Nastran +Y below) should point "out" of the aeroshell. This will ensure that the FEA loads are transformed correctly.
Abaqus Export
Beam orientations in Abaqus are defined with vectors or with an additional node.
In Abaqus, beams defined with additional nodes will take precedence over any beam orientation vector definition. It is for this reason that the preferred method of defining beam orientations is with additional nodes. Any beam orientation defined with vectors will be reprinted to the iteration FEM using additional nodes. This serves to preserve the integrity of the initial beam orientations.
Important: Beam orientations defined with third nodes are preferred to beam orientations defined with vectors.
