Dear Lysander,
The statement GFORCE/,…,FUNCTION=USER() described in the A2AD User’s Guide is the statement that calls AeroDyn, through A2AD, for each element of each blade in your ADAMS model. As I said in the post found here: [Adams-Aerodyn Interface), in order to run AeroDyn within ADAMS, you must compile the AeroDyn and A2AD source files into a DLL and link them to ADAMS using ADAMS’ cr-user command. You then run ADAMS with the ru-user command.
The reason I suggested you use FAST to create your ADAMS model in that post is because FAST does two things for you:
(1) FAST creates the ADAMS dataset of a wind turbine for you (including the necessary ADAMS statements, functions, and commands, such as the GFORCE statements).
(2) The A2AD source code includes all of the code need to link AeroDyn with ADAMS and to run FAST-generated ADAMS models.
See the “ADAMS Preprocessor” chapter of the FAST User’s Guide for more information.
Best regards,