Modeling the dynamic fracture and fragmentation of explosive-driven metal ring with notches or grooves

摘要

The dynamic fracture and fragmentation of notched rings under explosive loading were modeled to investigate the fragment characteristics (average fragment size and fragment size distribution) and their effects on fragmentation performance. An analytical model of the average fragment size was proposed for dynamic fracture and fragmentation based on energy criteria related to the material properties, strain rates, and notch effect. The theoretical solutions indicated that the notch effect was dominant with the decreased notch spacing. A law for the fragment size distribution was achieved by combining the binomial distribution. The theoretical distribution depended on the notch spacing, and the distribution was approximated by the natural fragmentation of rings with larger notch spacing. Dynamic fracture and fragmentation experiments were also conducted on cylindrical rings made of AISI 1020 steel. The experimental results were compared with the theoretical models. The average fragment sizes of the theoretical solutions agreed well with the experimental results, and the theoretical distribution provided a good description of the experimental data.