Determination of the spall strength from measured values of the specimen free-surface velocity

1983 ◽  
Vol 23 (5) ◽  
pp. 703-705 ◽  
Author(s):  
S. A. Novikov ◽  
A. V. Chernov
Keyword(s):  
Free Surface ◽  
Spall Strength ◽  
Surface Velocity ◽  
Free Surface Velocity

Dynamic Failure Behavior of Polycrystalline Alumina Under Impact Loading

2007 ◽  
Vol 74 (5) ◽  
pp. 990-995 ◽  
Author(s):  
Guowen Yao ◽  
Zhanfang Liu
Keyword(s):  
Free Surface ◽  
Spall Strength ◽  
Surface Velocity ◽  
Failure Behavior ◽  
Free Surface Velocity ◽  
Plate Impact ◽  
Polycrystalline Alumina ◽  
Failure Wave ◽  
Damage And Fracture ◽  
Impact Experiments

Plate impact experiments and impact recovery experiments were performed on 92.93wt.% aluminas using a 100mmdia compressed-gas gun. Free surface velocity histories were traced by a velocity interferometry system for any reflector (VISAR) velocity interferometer. There is a recompression signal in free surface velocity, which shows evidence of a failure wave in impacted alumina. The failure wave velocities are 1.27km∕s and 1.46km∕s at stresses of 7.54GPa and 8.56GPa, respectively. It drops to 0.21km∕s after the material released. SEM analysis of recovered samples showed the transit of intergranular microcracks to transgranular microcracks with increasing shock loading. A failure wave in impacted ceramics is a continuous fracture zone, which may be associated with the damage accumulation process during the propagation of shock waves. Then a progressive fracture model was proposed to describe the failure wave formation and propagation in shocked ceramics. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. Numerical simulation of the free surface velocity was performed in good agreement with the plate impact experiments. And the longitudinal, lateral, and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.

scholarly journals Identification of Ellis rheological law from free surface velocity

2019 ◽  
Vol 263 ◽  
pp. 15-23 ◽  
Author(s):  
Abdulrahman Al-Behadili ◽  
Mathieu Sellier ◽  
James N. Hewett ◽  
Roger I. Nokes ◽  
Miguel Moyers-Gonzalez
Keyword(s):  
Free Surface ◽  
Surface Velocity ◽  
Free Surface Velocity

Evaluation of Marangoni convection and free surface velocity of molten tungsten for tungsten divertor

2019 ◽  
Vol 140 ◽  
pp. 117-122 ◽  
Author(s):  
Kohei Hamaguchi ◽  
Eiji Hoashi ◽  
Takafumi Okita ◽  
Kenzo Ibano ◽  
Yoshio Ueda
Keyword(s):  
Free Surface ◽  
Marangoni Convection ◽  
Surface Velocity ◽  
Free Surface Velocity

scholarly journals Discussion on the physical meaning of free surface velocity curve in ductile spallation

2015 ◽  
Vol 64 (3) ◽  
pp. 034601
Author(s):  
Pei Xiao-Yang ◽  
Peng Hui ◽  
He Hong-Liang ◽  
Li Ping
Keyword(s):  
Free Surface ◽  
Physical Meaning ◽  
Velocity Curve ◽  
Surface Velocity ◽  
Free Surface Velocity

Free Surface, Velocity Gradient Flow Past Hemisphere

1970 ◽  
Vol 96 (7) ◽  
pp. 1485-1502
Author(s):  
Gordon H. Flammer ◽  
J. Paul Tullis ◽  
Earl S. Mason
Keyword(s):  
Free Surface ◽  
Velocity Gradient ◽  
Gradient Flow ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Flow Past

Jet Impingement of a Non-Newtonian Fluid

2006 ◽  
Author(s):  
Jiangang Zhao ◽  
Roger E. Khayat
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Hydraulic Jump ◽  
Similarity Solutions ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Viscous Boundary Layer ◽  
Boundary Layer Region ◽  
Layer Region ◽  
Viscous Boundary

The similarity solutions are presented for the wall flow which is formed when a smooth planar jet of power-law fluids impinges vertically on to a horizontal plate, and spreads out in a thin layer bounded by a hydraulic jump. This problem is formulated analogous to radial jet flow problem and the solution procedure is accounted for by means of similarity solution of the boundary-layer equation [1] for Newtonian fluids. For the convenience of analysis, the flow may be divided into three regions, namely a developing boundary-layer region, a fully viscous boundary-layer region, and a hydraulic jump region. The similarity solutions of the film thickness and free surface velocity in fully viscous boundary-layer region include unknown constant L, which is solved numerically and approximately in the developing boundary-layer flow region. Comparison between the numerical and approximate solutions leads generally to good agreement, except for severely shear-thinning fluids. The boundary-layer solution depends on two parameters: power-law index n and α, the dimensionless flow parameters. The effect of α on film thickness and free surface velocity is investigated. The relations between the position of the hydraulic jump and dimensionless flow parameter are obtained and the effect of α on the position of the jump is presented.

Messung des Chapman-Jouguet-Druckes mit Röntgen-Absorption

1981 ◽  
Vol 36 (5) ◽  
pp. 437-442
Author(s):  
K. Hollenberg ◽  
H.-R. Kleinhanß ◽  
G. Reiling
Keyword(s):  
Free Surface ◽  
Pressure Range ◽  
Detonation Front ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
High Explosives ◽  
X Ray ◽  
X Ray Absorption

Abstract The Chapman Jouguet pressure of some high explosives is measured by X-ray absorption giving the density behind the detonation front. An accuracy of 2 - 3% was achieved in the pressure range of 200 kbar. The pressures are considerably lower than comparable results of other authors obtained by the free surface velocity method or similar techniques.

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