How to extract a crack opening from a continuous damage finite-element computation?

Frédéric Dufour (1) , Gilles Pijaudier-Cabot (1) , Marta Choinska (1) , Antonio Huerta (2)

1 GeM - Institut de Recherche en Génie Civil et Mécanique
2 LaCàN - Laboratori de Càlcul Numèric (LACAN)

Doubtlessly, for assessing the integrity and the strength of concrete structures to environmental attacks it would be ideal to model the transition between diffuse damage and a discontinuous description. We propose, in a first approach, to extract an equivalent crack opening using a non local Mazars’ damage model. We consider a discontinuous displacement field with a given jump $[U]$ from which we compute the equivalent non local strain $\tilde{ε}([U])$ governing the damage variable in Mazars’ model. Besides, from a classical FE computation, we obtain a distribution of the state variable $\tilde{ε}^{FE}$ with the same shape due to the non local weight function. Finally the displacement jump is computed by setting $\tilde{ε}([U]) = \tilde{ε}^{FE}$ at the discontinuity. The proposed approach is applied on a tension rod with an error measure between both solutions to evaluate how the non local solution approaches asymptotically the representation of a discontinuity. Results show good agreement for large damage.

Domaines: Mécanique [physics.med-ph]; Matériaux

Frédéric Dufour, Gilles Pijaudier-Cabot, Marta Choinska, Antonio Huerta. How to extract a crack opening from a continuous damage finite-element computation?. Fracture Mechanics of Concrete and Concrete Structures:, 2007, Catane, Italy. ⟨hal-01008260⟩