Abstract
The present report was part of the proceedings at the 6th International Conference of Fracture Mechanics of Concrete and Structures (FRAMCOS) held in Catania, Italy; June 2007. In this work a modified version of the Holmquist-Johnson-Cook (MHJC) model was developed by the authors to handle impact and penetration problems in concrete. In this modified version a new continuous pressure-shear function is adopted where the influence of the third deviatoric stress invariant is considered; in addition, a new strain-rate sensitivity formulation is included and finally three damage variables describing the tensile cracking, shear cracking and pore compaction mechanisms are introduced. The model parameters are obtained for two concrete qualities and perforation of concrete slabs by pointed projectiles is considered numerically and compared with experimental results from the literature. Ballistic limit assessments with deviations under 8 % when compared to the experiments are obtained