FRACTURE PHENOMENA OF BRITTLE MATERIAL AGAINST A SHAPED CHARGE JET

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1475-1482 ◽  
Author(s):  
JOON HONG CHOI ◽  
SOON NAM CHANG
Keyword(s):  
Shock Wave ◽  
Crack Growth ◽  
High Speed ◽  
Slow Crack Growth ◽  
Fused Silica ◽  
Shaped Charge ◽  
Sonic Velocity ◽  
Crystalline Quartz ◽  
Single Crystalline ◽  
Shaped Charge Jet

In order to study the protection behavior of brittle materials against a shaped charge jet, the jet penetration and the fracture behavior have been investigated by the series of photographs taken by the IMACON high speed camera. The examined materials were glass, fused silica, and single crystalline quartz. The trend of crack growth in BK7 glass and fused silica indicated conical shape. In the case of the single crystalline quartz, it was observed that the crack grows fast along the axis of crystal growth. The velocity of shock wave (~ 6km/sec) into glass and fused silica was faster than the sonic velocity. However, the velocity of shock wave in the single crystalline quartz showed to be similar to its sonic velocity. The ballistic protection capability of single crystalline quartz showing fast crack growth has been evaluated to be lower than that of fused silica which has relatively slow crack growth, although the quartz has higher physical and mechanical properties.

The Development of Life Prediction Techniques for Structural Ceramics

1996 ◽  
Vol 118 (4) ◽  
pp. 847-855
Author(s):  
P. K. Khandelwal ◽  
N. J. Provenzano ◽  
W. E. Schneider
Keyword(s):  
Crack Growth ◽  
Life Prediction ◽  
High Speed ◽  
Failure Modes ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Department Of Energy ◽  
Bending Stresses ◽  
Prediction Techniques ◽  
Fast Fracture

One of the major challenges involved in the use of ceramic materials in advanced vehicular heat engines is ensuring adequate strength and durability. This Department of Energy supported activity has developed methodologies to predict the structural behavior of ceramic components. The effort involved the characterization of injection-molded and hot isostatic pressed PY6 silicon nitride and the development of analytical life prediction techniques. Three failure modes are addressed: fast fracture, slow crack growth, and creep rupture. The technique deals with surface as well as internal component failures. The life prediction methodologies for fast fracture and slow crack growth have been verified using two types of confirmatory specimens: (1) flat circular disks subjected to bending stresses, and (2) high-speed rotating spin disks. Correlation was achieved for a variety of test conditions and failure mechanisms. The predictions associated with surface failures proved to be optimistic, requiring re-evaluation of the components’ initial fast fracture strength. Correlation was achieved for the spin disks that failed in fast fracture from internal flaws. Time-dependent, elevated-temperature spin disk failures were also successfully predicted.

scholarly journals Dynamic fracture of inorganic glasses by hard spherical and conical projectiles

2015 ◽  
Vol 373 (2038) ◽  
pp. 20140135 ◽  
Author(s):  
M. Munawar Chaudhri
Keyword(s):  
Crack Growth ◽  
High Speed ◽  
Soda Lime ◽  
Fused Silica ◽  
Soda Lime Glass ◽  
Dynamic Crack ◽  
Inorganic Glasses ◽  
The Impact ◽  
Hertzian Cone ◽  
Crack Bifurcation

In this article, high-speed photographic investigations of the dynamic crack initiation and propagation in several inorganic glasses by the impact of small spherical and conical projectiles are described. These were carried out at speeds of up to approximately 2×10 6 frames s −1 . The glasses were fused silica, ‘Pyrex’ (a borosilicate glass), soda lime and B 2 O 3 . The projectiles were 0.8–2 mm diameter spheres of steel, glass, sapphire and tungsten carbide, and their velocities were up to 340 m s −1 . In fused silica and Pyrex, spherical projectiles' impact produced Hertzian cone cracks travelling at terminal crack velocities, whereas in soda-lime glass fast splinter cracks were generated. No crack bifurcation was observed, which has been explained by the nature of the stress intensity factor of the particle-impact-generated cracks, which leads to a stable crack growth. Crack bifurcation was, however, observed in thermally tempered glass; this bifurcation has been explained by the tensile residual stress and the associated unstable crack growth. A new explanation has been proposed for the decrease of the included angle of the Hertzian cone cracks with increasing impact velocity. B 2 O 3 glass showed dynamic compaction and plasticity owing to impact with steel spheres. Other observations, such as total contact time, crack lengths and response to oblique impacts, have also been explained.

scholarly journals Study on the Interference Process of Liquid Radial Reflux on the Stability of a Shaped Charge Jet

2021 ◽  
Vol 11 (17) ◽  
pp. 8044
Author(s):  
Youer Cai ◽  
Xudong Zu ◽  
Yaping Tan ◽  
Zhengxiang Huang
Keyword(s):  
Theoretical Analysis ◽  
Composite Structure ◽  
High Speed ◽  
Side Wall ◽  
Shaped Charge ◽  
Bottom Plate ◽  
Depth Of Penetration ◽  
X Ray ◽  
Shaped Charge Jet ◽  
Filled Composite

The process of liquid radial reflux interference during jet penetration in a liquid-filled composite structure is divided in this study into three stages: bottom plate reflection interference, side-wall reflection interference, and side-wall secondary reflection interference. The calculation model of the velocity interval of the disturbed jet and the residual penetration depth of the jet has been established through theoretical analysis. Results show that the liquid-filled composite structure can interfere with the high-speed section of the shaped charge jet. The accuracy of the theoretical analysis in this paper has been verified through numerical simulation, X-ray, and depth-of-penetration experiments. Among the results, those of the X-ray experiment show that the liquid-filled composite structure has interference on the tip of the shaped charge jet, which provides a possibility for the application of the liquid-filled composite structure to ammunition safety and other extreme cases.

Study on Shaped Charge Jet Initiation of Solid Rocket Motors

2019 ◽  
Author(s):  
Hao CUI ◽  
Rui GUO ◽  
Pu SONG ◽  
Jinsheng XU ◽  
Xiaohui GU ◽  
...  
Keyword(s):  
High Speed ◽  
Shaped Charge ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Jet Impact ◽  
Solid Rocket ◽  
Battlefield Environment ◽  
Shaped Charge Jet ◽  
The Impact ◽  
Jet Initiation

Abstract In order to study the mechanism of initiation of solid rocket motors under the impact of shaped charge jets, a shaped charge jet initiation test was experimentally studied to evaluate the safety of the motor under attack in the battlefield environment. The ex-perimental results indicated that the motor had a detonation reaction under the shaped charge jet impact. The response of the mo-tor was recorded by a high-speed camera. In addition, the mechanism of initiation of the propellant charge was evaluated using by numerical simulations. Pressure-time and reaction-time curves of propellants were analyzed in this paper.

scholarly journals The Development of Life Prediction Techniques for Structural Ceramics

1995 ◽  
Author(s):  
P. K. Khandelwal ◽  
N. J. Provenzano ◽  
W. E. Schneider
Keyword(s):  
Crack Growth ◽  
Life Prediction ◽  
High Speed ◽  
Failure Modes ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Department Of Energy ◽  
Bending Stresses ◽  
Prediction Techniques ◽  
Fast Fracture

One of the major challenges involved in the use of ceramic materials in advanced vehicular heat engines is ensuring adequate strength and durability. This Department of Energy supported activity has developed methodologies to predict the structural behavior of ceramic components. The effort involved the characterization of injection molded and hot isostatic pressed PY6 silicon nitride and the development of analytical life prediction techniques. Three failure modes are addressed: fast fracture, slow crack growth, and creep rupture. The technique deals with surface as well as internal component failures. The life prediction methodologies for fast fracture and slow crack growth have been verified using two types of confirmatory specimens: (1) flat circular disks subjected to bending stresses and (2) high speed rotating spin disks. Correlation was achieved for a variety of test conditions and failure mechanisms. The predictions associated with surface failures proved to be optimistic requiring reevaluation of the components initial fast fracture strength. Correlation was achieved for the spin disks that failed in fast fracture from internal flaws. Time dependent elevated temperature spin disk failures were also successfully predicted.

Effect of the high-speed impact of a shaped-charge jet on the strength of titanium alloys

2007 ◽  
Vol 52 (2) ◽  
pp. 204-208 ◽  
Author(s):  
V. N. Minakov ◽  
N. V. Minakov ◽  
V. Yu. Puchkova ◽  
N. D. Rudyk ◽  
G. E. Khomenko
Keyword(s):  
Titanium Alloys ◽  
High Speed ◽  
Shaped Charge ◽  
High Speed Impact ◽  
Shaped Charge Jet

Examination of Fracture Interfaces in Silicon Nitride

1975 ◽  
Vol 33 ◽  
pp. 60-61
Author(s):  
Nancy J. Tighe
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Grain Boundary Sliding ◽  
Boundary Phase ◽  
Turbine Engines ◽  
Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

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