Fatigue-induced stress redistribution in prestressed concrete beams modeled using the constitutive hypothesis of inter-aggregate degradation

Despite of intensive research on concrete fatigue, the transfer of fatigue characteristics determined at the material level to the structural level remains a challenging issue. In this paper, the propagation of fatigue-induced damage through the concrete structure is analyzed using a microplane fatigue model for concrete recently developed by the authors. To this end, our recent experimental study in which the fatigue propagation was monitored at the structural level represented by prestressed concrete beams is used to derive a general interpretation of the stress redistribution process using of the developed model. The numerical studies show that the developed microplane fatigue model provides a powerful computational tool for in-depth analysis of the correspondence between the fatigue behavior at the material and structural scales in a wide range of load configurations. In addition, the thermodynamically based constitutive model allows for the quantification of the energy dissipation during the process, revealing the possibility of deriving material-specific energetic characteristics that can further help to make the predictions of fatigue life more accurate.