2015 Vol. 29, No. 1

Display Method:
Single Shock Compression of Fluid Deuterium by QMC Simulation
LI Ming-Rui, ZHOU Gang, LI Zhi-Kang, GENG Bao-Gang, FAN Ru-Yu, ZHAO Nan
2015, 29(1): 1-8. doi: 10.11858/gywlxb.2015.01.001
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Abstract:

Since liquid hydrogen has some complex physical behaviors in a relatively wide range of pressure and temperature, one more accurate and appropriate ab-initio simulation method is urgently required.We used the Coupled Electron-Ion Monte Carlo (CEIMC) method to simulate the single shock compression experiment of deuterium, and systematically studied its thermodynamic properties under high pressure.It is shown that the liquid deuterium principle Hugoniot has a maximum compression ratio of 4.48 at about 50.3 GPa, but the compression ratio does not increase gradually around 110 GPa.By utilizing an appropriate aluminum impedance match model, we have established the correlations between the states of compressed deuterium and the shock or particle velocities in aluminum taken before the shock wave crossing the Al-D2 interface, and contemporarily summarized the physical processes of liquid deuterium under single shock compression in detail.The calculation results are not only in very good agreement with the existing experiments via different high-pressure generating technologies, but also consistent with the data above 100 GPa corrected from the Omega Laser driven experiment.Therefore, the CEIMC method combined with the wave function based on the resonant valence bond theory is very suitable for the simulations of shocked liquid deuterium.

Modification of Visco Statistical Crack Mechanics for PBXs
ZHANG Yan-Geng, LOU Jian-Feng, HONG Tao
2015, 29(1): 9-14. doi: 10.11858/gywlxb.2015.01.002
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Abstract:

Based on the Viscose-Statistical Crack Mechanics (Visco-SCRAM) model describing the dynamic response of PBXs', a modified model is obtained through changing the value scope of the direction vector of crack surface, the value of initial flaw size and the volumetric constitutive relation.Then the new model is applied in a finite element program.During the simulation process of the plate impact experiment for PBX JO-9159, the influence of crack number density parameter N0 is analyzed.Combined with the experimental data, the results simulated by the original and modified models are compared and analyzed.It is concluded that the modified model describes the damage and failure of PBXs under low-velocity impact more reasonably.

Calculation Analysis of the Impact Melting and Resolidification Process for the Bismuth Using the Ti-Cu-W Pillow Flyer
BAI Jing-Song, YU Ji-Dong, DAI Cheng-Da, WANG Yu, LIU Kun, LUO Guo-Qiang, SHEN Qiang, TAN Hua, WU Qiang, ZHANG Lian-Meng
2015, 29(1): 15-22. doi: 10.11858/gywlxb.2015.01.003
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Abstract:

Numerical simulations are carried out to design the Pillow flyer of Ti-Cu-W system, and the impact loading and quasi-isentropic loading of the bismuth sample are also carried out.We experimentally investigate the intricate physical process of impact melting and resolidification.Experiment results of wave profiles are similar with numerical ones.The complete equation of state of bismuth including five solid phases and one liquid phase is established.Triple points in phase diagram and the Hugoniot curve in high pressure area agree well with the experiment data.The temperature and phase transition information in impact loading and resolidification experiment are also obtained.According to the calculation analysis and interpretation of the experiment data, the loading experiment based on Ti-Cu-W flyer is available to study the physical process of impact melting and resolidification of bismuth, and an appropriate research method and effective technique means for experiment exploration is established.

Damage Effects of Explosion of RDX-Based Aluminized Explosives in Concrete
PEI Hong-Bo, NIE Jian-Xin, QING Jian-Feng, ZHOU Zheng-Qing
2015, 29(1): 23-28. doi: 10.11858/gywlxb.2015.01.004
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Abstract:

In order to investigate the damage effect of aluminized explosives in concrete, three types of aluminized explosive with different aluminum contents were blasted on small concrete targets.High speed camera was used to capture the blasting progress.Experimental results show that the depth of charge has important influence on the damage, and the damage effect at 30 cm buried depth is more serious than 10 cm buried depth.The aluminized explosives with aluminum content 15% has the best damage effect at 10 cm buried depth, which indicates that modest amounts of aluminum can increase the concrete blasting performance of aluminized explosives.

Three-Dimensional Numerical Investigation on Structure and Radial Variation of Rotating Detonation Flow Field
ZHANG Xu-Dong, FAN Bao-Chun, GUI Ming-Yue
2015, 29(1): 29-34. doi: 10.11858/gywlxb.2015.01.005
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Abstract:

Based on three-dimensional Euler equation and elementary reaction model of hydrogen/oxygen system which includes 8 species and 48 elementary reactions, the rotating detonation in the annular combustor was simulated numerically.The basic three-dimensional structure of the rotating detonation consists of detonation wavelet, oblique shock wave and slip line.Due to the special geometric configuration of rotating detonation combustion, the detonation strength near the inner wall is weaker than that near the outer wall, and the rotating detonation can propagate self-sustainingly finally.

Brillouin Scattering Study on Molecular Liquid under High Pressure and High Temperature Conditions
MA Chun-Li, WU Xiao-Xin, HUANG Feng-Xian, LI Min, WANG Xiao-Xia, ZHOU Qiang, LI Fang-Fei, CUI Qi-Liang
2015, 29(1): 35-41. doi: 10.11858/gywlxb.2015.01.006
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Abstract:

High-pressure and high-temperature Brillouin scattering studies have been performed on molecular liquids, including water (H2O), ammonia (NH3), ammonia dihydrate (NH3·2H2O) and methane (CH4) by using a diamond anvil cell (DAC).The acoustic velocity and adiabatic bulk modulus have been determined from measured Brillouin frequency shifts in both 180° and 60° scattering geometries under pressure up to freezing point, along room temperature (296 K) and high temperature (410 K) isotherms, and the pressure dependence of acoustic velocity and adiabatic bulk modulus were compared in different molecular systems.The acoustic velocities increase smoothly with the increasing pressure, methane possesses the highest velocity increasement and the lowest adiabatic bulk modulus under similar pressure and temperature, indicating the hydrogen bond impact on elasticity in these liquids.A change in the slope of pressure dependence of the bulk modulus in liquid ammonia dihydrate was observed around 1.5 GPa, suggesting a possible structure change in liquid and analysing the effect of hydrogen on elasticity.This study improves our understanding of the pressure- and temperature-induced molecular structure changes in other molecular liquid systems.

Mechanical Response of Fluorine Rubble F2311 under Quasi-Isentropic Compression
CAI Jin-Tao, WANG Gui-Ji, ZHANG Hong-Ping, ZHAO Feng, WU Gang, TAO Yan-Hui
2015, 29(1): 42-46. doi: 10.11858/gywlxb.2015.01.007
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Abstract:

The magnetically driven quasi-isentropic compression loading technique (ICE) is used to investigate the mechanical behavior of fluorine rubble F2311 which is often used in energetic composites.By means of laser displacement interferometer, particle velocities of the interface between F2311 and windows are gained under pressure up to 7.0 GPa.The mechanical characteristics of F2311 are analyzed by Lagrange and backward integration method.The results indicate that the response of the rubble F2311 could be described by the single-order us-up relation us=1.89+3.84up under 0-3.5 GPa, but under 3.5-7.0 GPa, this material displays a nonlinear response.

Equation of State of Detonation Products for RDX Explosive
ZHAO Yan-Hong, DUAN Su-Qing, LIU Hai-Feng, ZHANG Gong-Mu
2015, 29(1): 47-51. doi: 10.11858/gywlxb.2015.01.008
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Abstract:

The equation of state of detonation products for RDX explosive at different initial densities is calculated by adopting the program based on the statistical physics model.It is found that only gas phase product generates after the explosive detonation when the initial density of explosive is less than 1.20 g/cm3.With the increasing of initial density of explosive, solid carbon dissolves out after the explosive detonation.When the initial density of explosive is less than 1.60 g/cm3, the calculated detonation velocity and detonation pressure is in good consistent with the experimental value regarding the gas phase product as uniform mixing.With the increasing of initial density of explosive, the calculated detonation velocity and detonation pressure deviate largely from the experimental value.After detailed analysis, we find out that there is a supercritical fluid phase separation in this condition.Considering this effect in our program, a good result is obtained.

Study on Residual Stress of Big Tilling Depth Rotary Blade for Laser Shock Peening
XI Xiao-Bo, MIAO Hong, ZHAO Li, ZHU He-Lin, ZHANG Rui-Hong, JIN Yi-Fu
2015, 29(1): 52-58. doi: 10.11858/gywlxb.2015.01.009
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Abstract:

The effect of residual stress of big tilling depth rotary blade with 350 mm turning radius for laser shock peening (LSP) was researched, and the theoretical stress of rotary blade were analyzed by ANSYS.The stress concentration region was at the outer corner of tool shank.The LSP process was also simulated by ANSYS and the theoretical introduced value of the residual stress was obtained.Value of residual stress before and after LSP were tested by X-ray stress meter.The results show that the simulation value fits well with the experimental value, and the residual stress after LSP changes effectively with the maximum reaches 412.25 MPa and a amplification of 166%.The introduced residual compressive stress could eliminate the stress concentration of the working rotary blade, and raise its using life.It provides a new basis for further improvement and optimization of big tilling depth rotary blade's manufacture technique.

Preparation and Pressure-Induced Cubic-to-Orthorhombic Phase Transition in ZrW2O8
CHEN Xi-Ping, FANG Lei-Ming, SUN Guang-Ai, PENG Fang, CHEN Bo, HE Duan-Wei, LIU Jing
2015, 29(1): 59-62. doi: 10.11858/gywlxb.2015.01.010
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Abstract:

Negative thermal expansion (NTE) ZrW2O8 powders were prepared by solid-state reaction with ZrO2 and WO3 powders.In situ high-pressure X-ray diffraction measurements for powder ZrW2O8 were performed by using a diamond anvil cell (DAC) with synchrotron radiation facility.The result shows that powder ZrW2O8 is cubic phase with a little WO3.At about 0.27 GPa and room temperature, theα-ZrW2O8 phase transforms into a quenchable orthorhombic structure called the γ phase.Upon further compression, the γ phase becomes amorphous at the pressure of 3.81 GPa.The obtained bulk modulus of α-ZrW2O8 and γ-ZrW2O8 are (40.0±3.8)GPa and (37.0±3.0)GPa.

Simulation Study on Effects of Material Properties of the Bulging Flyers Driven by Colliding Detonation Waves
LIU Jun, WANG Yan-Jin, FENG Qi-Jing, ZHANG Shu-Dao
2015, 29(1): 63-68. doi: 10.11858/gywlxb.2015.01.011
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Abstract:

The elastic-plastic hydrodynamic L-R two-step Euler method was used for studying metal flyers colliding behaviors driven by cylinder explosion.The simulation results just accorded with the radio graphs when the flyer metal was lead, and the melting and spall phenomenons were described by simulation.And then, the formation mechanism of bulging part was researched.The material properties including melting points, strength, density and sound velocity, were investigated in this study.By analyzing the simulation results, some phenomenons are found out:the strong strength brings on an blunt bulging area; and the material sound velocity affects the pressure working time on colliding area, which is much more sensitive than the density and strength.

Influence of Concrete Target with Pre-Drilled Cavities on the Penetration Performance of a Projectile
WANG Hong-Bo, YANG Shi-Quan, XIE Ruo-Ze, QIAN Li-Xin, LU Yong-Gang
2015, 29(1): 69-74. doi: 10.11858/gywlxb.2015.01.012
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Abstract:

The sequence of events during the impact of tandem warhead system was divided based on the damage model of tandem warhead system to concrete target.Combined with the pre damage of front shaped charge to concrete target, the influence of concrete target with pre-drilled cavities on the penetration performance of a projectile was analyzed by numerical simulation, and the analysis results were partly validated by tests.The results of research indicate that the penetration depth of projectile increases when the number of pre-drilled cavity adds with the same cavity depth, but the increase of the penetration depth of projectile is unobvious when the number of pre-drilled cavity reaches some degree.The penetration over loading of projectile decreases along with the adding of the number of pre-drilled cavity when the the penetration depth of projectile is smaller than the depth of pre-drilled cavity, and the influence is slight when the penetration depth of projectile is larger than the depth of pre-drilled cavity.The penetration depth of projectile increases when the depth of pre-drilled cavity adds with the same cavity number.When the penetration depth of projectile is smaller than the depth of pre-drilled cavity, the penetration over loading of projectile becomes a decreasing stage, and the larger the depth of pre-drilled cavity, the longer the decreasing stage.While the influence is slight when the the penetration depth of projectile is larger than the depth of pre-drilled cavity.The results of research can be refered to optimize the design of tandem warhead system.

High-Pressure Induced Quenching of Polaron in the Emeraldine-Base Polymer
ZHOU Hong-Yu, LIU Jie
2015, 29(1): 75-80. doi: 10.11858/gywlxb.2015.01.013
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Abstract:

A hole polaron in the Emeraldine-base polymer under pressure was investigated on the basis of an extended Ginder-Epstein model.We found:the polaron relaxasion was weakened to disappear and the original local charge tended to distribute on the whole chain; Because of the pressure' excitation energy got lower so that the concentration of carriers got higher up to 12 orders of magnitude.In fact, we met a semiconductor-metal transition, our critic pressure was 13.76 GPa.Upon the pressure, there were electronic transitions from the top of the valence band to the bottom of the conduction band, the caculated peak of absorption was at 0.5 eV, which would be a spectrum evidence for the semiconductor-metal transition.