An elastoplastic constitutive model for concrete

A constitutive model for concrete, built within the framework of rate-independent theory of plasticity, is presented. The model invokes the concept of a failure locus which is introduced a priori as a path-independent criterion. The shape of the deviatoric section of this locus is influenced by the value of the confining pressure. The yield surface is assumed in a similar functional form to that of the failure locus, and its evolution is described in terms of a suitably chosen damage parameter. The plastic flow is governed by a non-associated flow rule. The material characteristics are strongly influenced by the actual confining pressure and display a smooth transition from a ductile to brittle behaviour. The procedure for identification of material parameters is explained in detail and the effectiveness of the concept is verified for a number of loading paths. The results of numerical simulations are compared with the experimental data available in the literature.