爆炸载荷下脆性颗粒体系破碎特性的数值研究

Experiments indicated that with spherical TNT as the central explosion source, the volume fraction of the particles composed of spherical glass beads and the broken particles in the spherical shell showed an exponential decay law with the increase of the M/C (the mass ratio of the spherical shell of the particle to the mass of the TNT).Using the DEM coupled with FEM, this paper reveals the propagation attenuation of the explosion wave in the particle annular shell after the central explosive is detonated and the sparse unloading process after reflection at the outer interface of the annular shell.Due to the short pulse characteristics of the blast wave, the internal stress field of the particles is always in a state of stress non-equilibrium, and the Weibull distribution of the particle crushing strength in the stress-equilibrium state will be much higher than the volume fraction of the broken particles measured by the test.Therefore, in this paper, the average induced stress rather than the instantaneous induced stress in the characteristic time of the breaking wave propagation is used as the stress index of the particle crushing strength, and the characteristic time of the breaking wave propagation is determined by the test results.In this paper, the influence of the non-uniformity of stress propagation on particle breakage is considered, and the variation law of the probability distribution of the mean induced stress peak value with the proportional distance is obtained.