Multiple Fatigue Events

Evaluating alternating stresses for multiple fatigue events depends on whether the events occur randomly or independently (no interaction between events). You can set the type of interaction between multiple fatigue events in the Fatigue dialog box.

No Interaction SOLIDWORKS Simulation evaluates the alternating stress separately for each event. Each fatigue event occurs independently from the other events. The damage factors from all events are added sequentially.
Random Interaction The software considers the possibility of mixing peak stresses from different events for the evaluation of alternating stresses.

The software evaluates the maximum alternating stress by considering all possible pairs of fatigue events at each node. It then uses the Miner’s rule and the ASME Boiler and Pressure Vessel Code to define a set of modified fatigue events.

The random interaction between events option predicts a higher damage factor than applying the defined events sequentially, unless the stress peaks from different events are marginally different. In such cases, it is recommended to run two fatigue studies; one study with no interaction between events and the other study with random interaction. The results can reveal that one option gives higher damage at some locations while the other option gives higher damage at other locations.