Model is representation of the system or physical behavior. Different fatigue models are built to understand and predict fatigue behavior of structural elements. They can be so called fatigue life models based on observation of element - like S-N curve. They can be more complex, taking into account change of material properties (phenomenological models, with residual stiffness and strength) or dealing with behavior of material and cracks (mechanistic).
Contributor: Bartlomiej Sawicki (ESR5)