peteroznewman
Subscriber

Read the ANSYS Help to understand what defining an Infinite Life means in this analysis.


Infinite Life


Stress Life Analysis


This option appears only if Type is set to History Data (non-constant amplitude loading) and defines what life will be used if the stress amplitude is lower than the lowest stress on the SN curve.


In your model, the stress amplitude is not lower than the lowest stress on the SN curve, so it calculates Life from the SN curve. 


When you plot Life, it shows that the minimum value on the legend is 1171 and shows you where on the part that minimum value can be found. This means that the part will have a 50% probability of failure at that location after it has been exposed to 1171 repetitions of that loading history.


If you were to replace that loading history with one where the amplitudes were 1000 times smaller, then you might find that the Life plot will show 1e6 cycles as the minimum life.