Damage model for fatigue loading of concrete

A three-dimensional model for the description of fatigue behavior is proposed. The model is based on damage mechanics and uses a thermodynamics potential formulated for this class of materials by Dragon et al. [Comput. Meth. Appl. Mech. Eng. 183 (2000) 331] and Halm and Dragon [Eur. J. Mech. A Solids 17 (3) (1998) 439]. In this approach, a second-order tensor is introduced to describe the anisotropic character of the microcracked material. It is assumed that nucleation and growth of microcracks are governed by tensile strains. The model allows accounting for the accumulation of the damage for loading levels below the damage yield surface used in the classical models. An application to the case of concrete under compression has been carried out. The reliability of the model is assessed through comparison with experimental results of fatigue tests reported in the literature.