Forces can be obtained a variety of ways:
You can obtain interior forces and moments at a cross-section via the commands *DATABASE_CROSS_SECTION and *DATABASE_SECFORC. Note that when the "set" option is used in defining a cross-section, a node set identifying the path of the cross-section AND at least one element set identifying the elements to ONE SIDE of the cross-section must be provided.
You can obtain externally applied forces on nodes or groups of nodes via the commands *DATABASE_NODAL_FORCE_GROUP and *DATABASE_NODFOR.
You can obtain forces associated with boundary conditions via the command *DATABASE_BNDOUT.
You can obtain forces specifically associated with *BOUNDARY_SPC by including the command *DATABASE_SPCFORC.
Resultant contact forces are written via the command *DATABASE_RCFORC. In the case of single surface contact, you would also need *CONTACT_FORCE_TRANSDUCER_(option) to extract resultant contact forces generated by the single surface contact.
Contact forces on individual nodes are written via *DATABASE_NCFORC. One or both of the "print flags" SPR, MPR in *CONTACT must be set to 1 to identify the areas where nodal contact forces are to be extracted.
The data is written into the ASCII files SECFORC, NODFORC, BNDOUT, SPCFORC, RCFORC, and NCFORC.