D3PLOT 22.1
Frame of Reference: Computing the Local Coordinate System
Frame of reference: computing the local coordinate system
The local coordinate system used for thick shells is computed in much the same way as for shells, except that the average of the bottom (N1N2N3N4) and top (N5N6N7N8) faces is used to produce a "middle" face. The formulae are, as with shells:
| X' | = | N1N2 approximately: the true X' vector is recomputed below | |
| Z' | = | N1N3 x N2N4 | (Where x is a vector cross-product) |
| Y' | = | Z' x X' | |
| X' | = | Y' x Z' This final transformation is required to correct for any warping | |
In the case of a 6 noded thick tria Z' is obtained from N1N2 x N1N3