Input deck syntax

Declare the usage of a user element:

*USER ELEMENT,TYPE=U1,NODES=2,INTEGRATION POINTS=2,MAXDOF=6

Specify its properties

*BEAM SECTION, SECTION=GENERAL, ELSET=<elset_label>, MATERIAL=<Material>

First line
cross-section area $A$,
2nd order moment $I_{22}$,
2nd order deviation moment $I_{12}$ (must be zero!),
2nd order moment $I_{33}$,
shear correction factor $\kappa$.
Second line
Global $\hat X$-coordinate of local cross-section main axis $X_2$,
Global $\hat Y$-coordinate of local cross-section main axis $X_2$,
Global $\hat Z$-coordinate of local cross-section main axis $X_2$.