RESUMEN
The accidental initiation of explosives under mechanical loads has caused numerous catastrophic events. Therefore, the dynamic damage behavior of confined polymer-bonded explosives (PBXs) must be assessed to improve their practical applicability. In this study, polymer-bonded sugar (PBS) materials were prepared using a novel agglomerate to develop a PBX substitute material with enhanced experimental safety. The mechanical properties of the PBS shell were evaluated using a dynamic compression test, which revealed that the compression response of the shell was affected by the strain rate. A low-velocity impact experiment was performed to investigate the dynamic damage and load transfer characteristics of the PBX substitute. A constitutive model was developed to characterize the mechanical response of PBS subjected to high strain rates, and implementing this model in ABAQUS ensured successful prediction of the damage evolution process associated with PBS. Simulation results indicated that the PBS specimen was primarily damaged around its center while sliding friction was dominant near the center during pressure application. Notably, different stress states result in distinct crack growth velocity histories along the axial direction, with the damage ratio progressively decreasing toward regions closer to the impact surface.
RESUMEN
The scattering of fragments is a notable characteristic of the explosive detonation of a shelled charge. This study examines the fracture and fragmentation of the shell and the process by which natural fragments form under the strains of implosion. The analysis takes into account both the explosive's energy output and the casing's dynamic response. For this purpose, utilizing a thermochemical code as an alternative to the conventionally employed cylinder test, the Jones-Wilkins-Lee equation of state (JWL EOS) was calibrated within a range of relative specific volume up to 13. The detonation of the shelled charge was subsequently analyzed using the continuum-discontinuum element method (CDEM). Following this, the formation mechanisms and scattering characteristics of natural fragments were scrutinized. The analysis found that the shell predominantly experiences shear failure with uniform evolution, displaying a "hysteresis effect" and two mutation stages in the evolution of tensile failure. Within the JWL EOS's calibrated range, the representation of fragment displacement and velocity improved by 47.97% and 5.30%, respectively. This study provides valuable guidance for designing the power field of warheads and assessing their destructive power.