Numerical modelling of concrete fracture processes under dynamic loading: Meso-mechanical approach based on embedded discontinuity finite elements

This paper deals with 2D numerical modelling of concrete fracture under dynamic loading. For this end, a mesoscopic modelling approach with an explicit representation of aggregates and different fracture types by rate-dependent embedded discontinuity finite elements is developed. The mortar fracturing is governed by pre-embedded multiple discontinuity finite elements. The aggregates may fail according to the principal stress criterion (mode I) with a single embedded discontinuity. The numerical examples demonstrate that the present model captures many of the experimentally observed features of concrete under low and intermediate strain rates in tension and compression as well as in dynamic Brazilian disc test on concrete. Particularly, the simulations corroborate the hypothesis that the dynamic increase of strength in uniaxial compression and in Brazilian disc test (i.e. the indirect tensile strength) is caused by structural effects due to lateral inertia while in uniaxial direct tension it is a genuine material effect.