FRAGMENTATION SIMULATION OF ANNEALED AND HARDENED STEEL CYLINDERS USING AN ADVANCED MESHLESS NUMERICAL METHOD INTEGRATING A FRACTURE MODEL ADDRESSING TENSILE AND SHEAR FAILURE MODES

The natural fragmentation of ductile steel cylinder-shape explosive charges has been modelled on ABSTRAO software by means of a tailor made model combining physical descriptions of involved mechanisms and a modern Smooth Particle Hydrodynamics (SPH) method. This numerical approach differs from conventional Finite-Elements Methods-based calculations by being mass-conservative and by applying no constraint to fracture paths while overcoming tensile instability typical of standard SPH formulations. Within this software environment, the tensile mode I fracture and the mode II adiabatic shear bands-induced failure mechanisms are synchronously addressed by dedicated models based on relevant parameters fitted through an experimental comprehensive approach. These damage effects are focused around strain localizations induced by a correlated stochastic distribution of the material yield stress, this distribution accounting for volume defects. Comparisons between numerical and experimental fragments matrices are quite satisfying, highlighting the relevance of the proposed model.