Dear Mehdi, thanks for your help. I tried to find more information about amplitude values or load values in history output, but I couldn't find anything in the documentation (I am using Abaqus 6.12). Could you please give me some more details on what to specify in the history output request? Or do you have a link to the chapter of the documentation relating to this problem? Thank you.
Victor J. Аdlucky, thank you for the hint. According to the manual, AMPCU should be written automatically to the .odb file (and can not be requested by name). Thus, it should appear in the output, but it doesn't. I will check if I missed something by viewing the output database.
Manigandan Sekar, but the inut file is written at the beginning of the analysis, how can the amplitude values of my UAMP be written into that file during the simulation?
You can simply open a file in your subroutine and write to it with standard Fortran commands - just be aware that some file numbers are reserved for msg or dat files.
One more possibility is to use available history output for variable controlled by amplitude. This output is proportional to amplitude (=predefined magnitude*amplitude).
Thank you all for your answers and your help. It seems that there is no (simple) possibility to write the amplitude value to the output file. I have to go on writing the values in an extra file.
It can be possible by using the utility subroutine with UAMP see section:
2.1.16 Obtaining sensor information
The utility returns sensor values (one state variable in your case)
After that you need to update your input file (only the Keyword *output, history) by adding the optional parameter SENSOR. This will record sensor values = New History Output Request.