[pt] Este trabalho consiste no desenvolvimento de um modelo numérico para simular o fraturamento em estruturas de concreto. Como ferramentas principais são utilizados o Método dos Elementos Finitos (MEF) e alguns conceitos da Mecânica da fratura aplicada ao concreto. A principal palavra-chave que caracteriza este trabalho é o -elemento de interface-. Este elemento finito permite modelar descontinuidades na malha de elementos finitos entre as arestas dos elementos. Neste trabalho, estes elementos são utilizados para representar fissuras em estruturas de concreto. A modelagem destas fissuras é suportada por um conceito de fissura discreta, o qual está acoplado a um modelo constitutivo elástico com amolecimento, específico para a fissura ou para o elemento de interface.Neste trabalho, as análises não-lineares abrangeram sistemas estruturais com modo de fraturamento I. / [en] This work consists in the development of a numerical model in order to simulate the fracture process in concrete structures. This model is supported by concepts of the Finite Element Method and the Fracture Mechanics applied to concrete. The main keyword which characterizes this work is interface element. This finite element permits the modelling of discontinuities in the finite element mesh among the edges of the elements. In this work, these elements are used to represent cracks in concrete structures. The cracks modelling is supported by the discrete crack concept, which is associated to a constitutive model called elastic-softening, specific for the crack or for the interface element. In this work, the nonlinear analyses were limited to structural systems under fracture mode I.This work consists in the development of a numerical model in order to simulate the fracture process in concrete structures. This model is supported by concepts of the Finite Element Method and the Fracture Mechanics applied to concrete. The main keyword which characterizes this work is interface element. This finite element permits the modelling of discontinuities in the finite element mesh among the edges of the elements. In this work, these elements are used to represent cracks in concrete structures. The cracks modelling is supported by the discrete crack concept, which is associated to a constitutive model called elastic-softening, specific for the crack or for the interface element. In this work, the nonlinear analyses were limited to structural systems under fracture mode I.This work consists in the development of a numerical model in order to simulate the fracture process in concrete structures. This model is supported by concepts of the Finite Element Method and the Fracture Mechanics applied to concrete. The main keyword which characterizes this work is interface element. This finite element permits the modelling of discontinuities in the finite element mesh among the edges of the elements. In this work, these elements are used to represent cracks in concrete structures. The cracks modelling is supported by the discrete crack concept, which is associated to a constitutive model called elastic-softening, specific for the crack or for the interface element. In this work, the nonlinear analyses were limited to structural systems under fracture mode I. / [es] Este trabajo consiste en el desarrollo de un modelo numérico para simular fracturas en extructuras de concreto. Se utilizan como herramientas principales el Método de los elementos Finitos (MEF) y algunos conceptos de la Mecánica de la fractura aplicada al concreto. La principal palabra clave que caracteriza este trabajo es el -elemento de interfaz-. Este elemento finito permite modelar discontinuidades en la malla de elementos finitos entre las aristas de los elementos. En este trabajo, los elementos son utilizados para representar fisuras en extructuras de concreto. El modelo de estas fisuras se soporta por un concepto de fisura discreta, que está acoplado a un modelo constitutivo elástico, específico para la fisura o para el elemento de interfaz. En este trabajo, los análisis no lineales consideran sistemas extructurales con modo de fractura I.