Lab. de Calcul Numeric, Univ. Politecnica de Catalunya, Barcelona, Spain ` ` ` 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…
Lab. de Calcul Numeric, Univ. Politecnica de Catalunya, Barcelona, Spain ` ` ` 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 ε˜([U]) governing the damage variable in Mazars’ model. Besides, from a classical FE computation, we obtain FE a distribution of the state variable ε˜ with the same shape due to the non local weight function. Finally the FE displacement jump is computed by setting ε˜([U]) = ε˜ at the discontinuity. The proposed approach is applied onatensionrodwithanerrormeasurebetweenbothsolutionstoevaluatehowthenonlocalsolutionapproaches asymptotically the representation of a discontinuity. Results show good agreement for large damage. 1 INTRODUCTION many authors have tried to bridge both theories. The The assessment of the diffuse damage and the crack key parameter of such an approach is the thresh- opening is a key parameter to estimate the integrity old upon which the discontinuity is activated and the andthestrengthofconcretestructurestoenvironmen- crack starts to open. Usually, it is considered that the tal attacks ruled by diffusion and/or Darcy’s transfers.