Modelos de armadura e aderência para análise não-linear de estruturas de concreto armado

Abstract

This work discusses the nonlinear finite element analysis of reinforced concrete structures, using several reinforcement and bond-slip models.Plane and axis-symmetric finite elements are used to represent the concrete. To the reinforcement bars, the discrete, embedded and axis-symmetric point reinforcement elements are adopted. To treatment of the bond between materials, the bond-link and contact models canbe used or it can be incorporated into the embedded reinforcement element. The constitutive behavior of the concrete, reinforcement bar and concrete-steel interface region, is described by appropriate nonlinear models: the damage and microplane models to concrete, elastoplastic to steel and different stress-slip laws to bond. The incremental-iterative methods used to perform the equilibrium paths and some materialsconstitutive models, are briefly discussed. A detailed study about the main models to include the reinforcement and to treatment of the bond lost is presented. The models implementation, as expansion of an object oriented computational program, is also discussed. Some numerical simulations of reinforced concrete members, subjected to different strainstates, are presented. These simulations are compared with experimental results in order to validate the implemented models.The discussion of the results shows that the modeling tools utilized permit better comprehenssion of the deterioration and collapse of the reinforced concrete structures.