Daniel Shaw
Ansys Employee

The Mechanical Fatigue Tool (FT) supports the “History Data” loading type (often referred to as “Time Series loading”).  With history data loading, you associate a history data file (ASCII file containing load multipliers – usually vs time) with a Mechanical result set.  The FT creates a stress history using he stresses in the FE result set and the multipliers in the history data file.  The FT automatically uses rainflow counting to divide the stress history into bins of alternating stress and mean stress. 

If you have 2 different load history files that are associated with different FE loadings (e.g. FX and FY), you must run separate FEAs and do separate FT calculations.  You can then use Fatigue Combinations to linearly sum the damages (Miner’s rule).