Answer:
Yes, it is possible using the load generator.In the "Tools" menu, you can find the "From Motion..." command under "Generate Loads".
In the "Generate Loads From Motion" dialog box, you can define acceleration a in [m/s²], which can be used to determine a load, depending on the mass of the structure.
In RSTAB, it is thus possible to generate a load on a member. In RFEM, on a member, surface, or solid.
Important: The program uses the dead load of the structure. The mass of a specific load case cannot be applied here.