Mechanisms of fragmentation and microstructure of debris generated during explosive testing of Al-W granular composite rings

18th APS-SCCM; 24th AIRAPT

Chiu, Po-Hsun^1 ; Olney, K.L.^2 ; Braithwaite, C.^3 ; Jardine, A.^3 ; Collins, A.^3 ; Benson, D.J.^4 ; Nesterenko, V.F.^1,2

Materials Science and Engineering Program, University of California, San Diego, San Diego

CA

92027, United States^1

Department of Mechanical and Aerospace Engineering, University of California, San Diego, San Diego

CA

92027, United States^2

SMF Group, Department of Physics, Cavendish Laboratory, Cambridge

CB3 0HE, United Kingdom^3

Department of Structural Engineering, University of California, San Diego, San Diego

CA

92027, United States^4

关键词: Characteristic size;    Cold isostatic pressing;    Expanding ring experiment;    Finite element simulations;    Fragmentation mechanism;    Heterogeneous materials;    Homogeneous samples;    Polyhedral particles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/11/112017/pdf
DOI  :  10.1088/1742-6596/500/11/112017

来源: IOP

【 摘 要 】

Highly heterogeneous materials comprised of elements with drastically different densities and shock impedances (e.g., Al and W) may provide additional mesoscale fragmentation mechanisms reducing the characteristic fragment size in comparison with solid materials with similar density (e.g., Stainless Steel 304). Explosively driven expanding ring experiments were conducted with Al-W granular composite rings, processed using hot and cold isostatic pressing, with different morphologies (W polyhedral particles or W rods with high aspect ratio and bonded/unbonded Al spherical particles with different sizes). In comparison to homogeneous samples with a similar density, these granular/porous composites generated fragments with a significantly smaller characteristic size. Scanning Electron Microscopy revealed that fragments had a propensity to be composed of clustered Al and W particles. Finite element simulations were conducted to gain an insight into the mesoscale fragmentation mechanisms and the clustering behavior observed in the experiments. Understanding the mesoscale mechanisms of explosively driven pulverization is important for tailoring the size of the fragments through the alteration of mesostructural properties.