Particle morphology and packing effects on the shock loading of powders

Page N.W. (1994) Particle morphology and packing effects on the shock loading of powders. Shock Waves, 4 2: 73-80. doi:10.1007/BF01418570


Author Page N.W.
Title Particle morphology and packing effects on the shock loading of powders
Journal name Shock Waves   Check publisher's open access policy
ISSN 0938-1287
Publication date 1994
Sub-type Article (original research)
DOI 10.1007/BF01418570
Volume 4
Issue 2
Start page 73
End page 80
Total pages 8
Publisher Springer-Verlag
Subject 2211 Mechanics of Materials
2206 Computational Mechanics
Abstract A physically based model for the shock Hugoniot of a powdered material is described which allows separate identification of the cold and thermal contributions to pressure and specific internal energy. Special features of this model are provision for the effects of porosity on the stress state and an empirically determined cold loading contribution to pressure. The model was tested against published Hugoniot data for iron and gave excellent agreement for shock pressures ranging from low to high values. This shock Hugoniot was used to explore the shocked state of 4 samples of iron powder derived from commercially available material. The purpose of this study was to investigate the effect of powder particle characteristics and initial starting densities on the shocked state. The powder samples investigated had a range of morphologies and sizes. Powders with either a large shape factor or high internal friction, as determined in shear cell experiments, exhibited a higher stiffness in the cold loading curve. In the shocked state, this translated into a higher cold component of pressure and energy than found in the other powders. The effect of initial powder density was studied by applying the Hugoniot model to two impact initiated shock loadings, one for a stainless steel flyer impacting at 0.5 km/s and one at the higher velocity of 2.0 km/s. Both were applied to iron powder targets preloaded to a range of initial densities. For a given impact event, the proportion of shock energy in the thermal mode was found to decrease with increasing initial density. This decrease was more pronounced at higher shock strengths. As a result of the decreasing component of thermal energy with higher initial density, there was a reduction in the continuum temperature behind the shock. However, the corresponding increase in the component of cold energy with the falling relative contribution from the thermal energy lead to increasing density behind the shock suggesting that there is a trade off in terms of temperature and density achievable with a given impact event.
Keyword Particle morphology
Powder compaction
Shock loading
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import
 
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