Viscous Hardening Plasticity for Concrete in High-Rate Dynamics

Abstract

This paper presents a constitutive model for concrete in high-rate dynamics. The main feature outlined in this paper concerns the modeling of strength enhancement due to rate effects at the macrolevel of material description. It is accounted for in the constitutive modeling of strain and stresses within the theory of elastoplasticity by extending the classical plastic model to viscous hardening plasticity. Rate effects are associated with a viscous phenomenon occurring within the pores of concrete. The model is worked out in a thermodynamic framework which allows to account for couplings between viscous and plastic evolutions. The determination of the material parameters associated with the viscous phenomenon is achieved by using available data from dynamic direct tensile tests. By way of example, the three-parameter Willam-Warnke plasticity criterion is adapted to account for isotropic viscous hardening. Finally, some applications are shown to illustrate the capabilities of the model to capture the basic features of concrete behavior in high-rate dynamics, with a minimum of material parameters of clear physical significance and accessible by existing material tests.