Thermomechanical fatigue life simulation using the phase field method

Putting a mechanical structure under repeated cyclic loading can lead to fatigue crack initiation and propagation. In engineering processes, a fatigue crack evolution behavior can be very complicated when the structure is in a complex environment and under complex loading conditions. Over the years, different phase field models have been developed to simulate fatigue fractures; however, they are mostly restricted to fatigue under pure mechanical loading. In this work, we show that the phase field model can simulate fatigue behavior in a complex environment. As a highlight of the presented paper, we extended the phase field fatigue model to handle thermomechanical fatigue. We consider thermal stress to be an additional fatigue driving force in the phase field model. It is shown, using case studies, that the extended phase field fatigue model is able to predict thermomechanical fatigue behavior.