Dynamic experiments with Al-W granular/porous composites revealedqualitatively different behavior with respect to shear localization dependingon bonding between Al particles. Two-dimensional numerical modeling was used toexplore the mesomechanics of the large strain dynamic deformation in Al-Wgranular/porous composites and explain the experimentally observed differencesin shear localization between composites with various mesostructures.Specifically, the bonding between the Al particles, the porosity, the roles ofthe relative particle sizes of Al and W, the arrangements of the W particles,and the material properties of Al were investigated using numericalcalculations. It was demonstrated in simulations that the bonding between the"soft" Al particles facilitated shear localization as seen in the experiments.Numerical calculations and experiments revealed that the mechanism of the shearlocalization in granular composites is mainly due to the local high strain flowof "soft" Al around the "rigid" W particles causing localized damageaccumulation and subsequent growth of the meso/macro shear bands/cracks. The"rigid" W particles were the major geometrical factor determining theinitiation and propagation of "kinked" shear bands in the matrix of "soft" Alparticles, leaving some areas free of extensive plastic deformation as observedin experiments and numerical calculations.
展开▼
