A fatigue damage model for seismic response of RC structures

Numerous damage models have been developed in order to analyze seismic beha vior. Among the different possibilities existing in the literature, it is v ery clear that models developed along the lines of continuum damage mechani cs are more consistent with the definition of damage as a phenomenon with m echanical consequences because they include explicitly the coupling between damage and mechanical behavior. On the other hand, for seismic processes, phenomena such as low cycle fatigue may have a pronounced effect on the ove rall behavior of the frames and, therefore, its consideration turns out to be very important. However, most of existing models evaluate the damage onl y as a function of the maximum amplitude of cyclic deformation without cons idering the number of cycles. In this paper, a generalization of the simpli fied model proposed by Cipollina et al. [Cipollina A, Lopez-Hinojosa A, Flo rez-Lopez J. Comput Struct 1995;54:1113-26] is made in order to include the low cycle fatigue. Such a model employs in its formulation irreversible th ermodynamics and internal state variable theory. (C) 2000 Civil-Comp Ltd. a nd Elsevier Science Ltd. All rights reserved.