"Basic" Components for All Beams
Basic components for all beams
All beams types generate a "basic" force and moment vector (even if some of them populate it entirely with zeros!). This is [ Fx, Fy, Fz, Mxx, Myy, Mzz ], where all results are written in the local axis system for beams. The D3PLOT components have the names:
The local axis system for beams is derived as follows:
If N1N2 is the vector from node 1 to node 2:
| X' | = | N1N2 | |
| Z' |
= |
N1N2 x N1N3 | (Where x is the vector cross-product) |
| Y' | = | Z' x X' | |
The "third" node (N3) is the orientation node for the beam, serving only to
define its local Y' axis. It has no structural significance. If the representation
of beam local axes during post-processing is important throughout an analysis
you should consider defining separate "third" nodes for each beam element, and
setting the <
nrefup
> field on the
*CONTROL_OUTPUT
card to update these nodes' coordinates.