SACS Fatigue Extract is limited to extracting information from the current fatigue analysis and does not include any information about previous fatigue analyses. The reason for this is that only the fatigue damage information is transferred through fatigue damage file, so things like transfer function and response spectrum plotting, SCF recalculation, and other redesign features would not function correctly.  You can do each fatigue analysis individually through its own Fatigue Extract file.

Alternatively, you can define multiple fatigue cases in the same fatigue input file using the Fatigue options to specify multiple common solution files. This would result in the combination of the fatigue results into one fatigue extract file.