高压物理学报

Influence of H Additive on the Synthesis of cBN and Temperature-Distribution in the Anvil

BU Yu-Zhou, GUO Wei-Li, MA Hong-An, CHEN Li-Xue, JIA Xiao-Peng

2005, 19(1): 1-4 . doi: 10.11858/gywlxb.2005.01.001

PDF (827)

Abstract:
The influence of H in using Li3N as catalyst on the synthesis of cBN under high-temperature and high-pressure has been investigated. From the observation of cBN crystals growth within the sample capsule, the temperature gradient distribution has been discussed.

Pressure Effects on the Band Structure of BCC Lithium with Substitutional Hydrogen Defect

LIU Zhi-Ming, CUI Tian, HE Wen-Jiong, ZOU Guang-Tian, WEI Meng-Fu, CHEN Chang-An

2005, 19(1): 5-9 . doi: 10.11858/gywlxb.2005.01.002

PDF (761)

Abstract:
The pressure effects on the band structure of bcc lithium with substitutional hydrogen defect are studied by using ab initio pseudopotential-plane wave method at 0 K temperature. Even though the impurity hydrogen atom localizes a free electron in the sea of metallic valence electrons, the doped system still acts as metal, but an isolated band and a band gap appear under Fermi level, the lowest metallic band is distorted at Gamma point, and elsewhere in other conduction and valence bands. When pressures applied on the system, the band gap is widened and the isolated band tends to be stretched horizontally into a line, just like an energy level.

Application of the Velocity Potential Model to Penetration Study

WANG Zheng, NI Yu-Shan, CAO Ju-Zhen, ZHANG Wen, JIN Wu-Gen

2005, 19(1): 10-16 . doi: 10.11858/gywlxb.2005.01.003

PDF (718)

Abstract:
With the application of Rubin's penetration theory and the velocity potential model, some new results of penetration problem are presented in this paper. A code according to this model was written to calculate penetration problems of long rod projectile with conical-nose, ogive-nose and spherical nose. The results of penetration depths and residual velocity were compared with the experimental data to analysis the adaptability of the model to varied kinds of noses. The comparison showed that the results given by the theoretical penetration model are in good agreement with the experiments for ogive-nose rod projectile. Then we used the theoretical penetration model to study the scaling penetration problems of ogive-nose projectile impacting on aluminum targets. The calculated results testified the conclusion that the normalized penetration depths and residual velocity are equal. Meanwhile we drew an important conclusion that the deceleration of the projectile are inverse proportion to the size. Finally, using the theoretical model, we made a trial to calculate penetration problems of the concrete targets, presented some results consistent with the experiments, and gave a delicate analysis.

Numerical Simulation of Different Cavities Compression by the High Pressure

BAI Jing-Song, LI Ping, ZHONG Min, JIANG Yang, ZHANG Zhan-Ji, YU Ji-Dong

2005, 19(1): 17-23 . doi: 10.11858/gywlxb.2005.01.004

PDF (683)

Abstract:
We have applied the combination of PPM and VOF methods with Lagrange-Remapping algorithm for simulation of the various cavities compressed by the high pressure loading. The physical processes of the multi-fluid interactions are calculated in high accuracy. This method also shows the potential for dealing with the problems of high density or high pressure ratio flows.

One-Dimensional and Two-Dimensional Computation of Metal Spallation Induced by Laser

TAN Fu-Li, LI Yong-Chi, GUO Yang, CAO Jie-Dong

2005, 19(1): 24-28 . doi: 10.11858/gywlxb.2005.01.005

PDF (795)

Abstract:
A thermo-visco-plastic constitutive relation for the metal, which can cover plastic hardening (softening) behaviors, thermo-softening behaviors and damage-softening behaviors, is adopted in the numerical computation for analyzing the metal spallation induced by laser. Computations are carried out in one-dimensional and two-dimensional cases, respectively. Attenuation of shock wave pressure is calculated, as well. The calculated spallation thickness is in good agreement with the experimental observations.

Experimental Study on Impedance Spectra of Iherzolite under High Temperature and High Pressure

DAI Li-Dong, LI He-Ping, LIU Cong-Qiang, SU Gen-Li, CUI Tong-Di, SHAN Shuang-Ming, YANG Chang-Jun, LIU Qing-You

2005, 19(1): 29-34 . doi: 10.11858/gywlxb.2005.01.006

PDF (833)

Abstract:
The electrical conductivities of the iherzolite were measured by virtue of SARLTON-1260 frequency and phase impedance spectroscopy analyzer in situation of 1.0~4.0 GPa, 1 073~1 573 K and 10-1～107 Hz frequency ranges. The experimental results indicate that the complex impedance spectra of iherzolite strongly depends on frequency, at the same time we explain it by virtue of electrical conduction: grain boundaries, grain interiors as well as between sample and electrode; the temperature is an important parameter deciding the electrical conductivity. As temperature increases, the electrical conductivity augments. The relationships between lg and 1/T accord with Arrenhius relation formula; this is the first time that the pressure as a controlling ingredient is well brought forward: As the pressure increases, the block rate advances; at the same time the electrical conductivity decreases.

Ultrasonic Measurement and Isothermal Equation of State for LY12Al under Static Pressures

ZHANG Ting, BI Yan, ZHAO Min-Guang

2005, 19(1): 35-40 . doi: 10.11858/gywlxb.2005.01.007

PDF (1005)

Abstract:
The sound velocities of longitudinal wave and transverse wave for LY12Al were measured under static pressures using pulse echo overlap technique. According to the bulk modulus at zero pressure, KS0, and its pressure derivative KS0 yielded from the ultrasonic meansurements under very low pressures (0.5 GPa), three Isothermal Equations of StateMurnaghan EOS, Birch-Murnaghan EOS and Vinet EOS for LY12Al were reduced. It was found that the Vinet EOS deduced from ultrasonic data was adequate for describing the compressibility of aluminium and its alloy with fcc structure, even up to 200 GPa. Furthermore, the zero pressure Debye temperature and thermodynamic Grneisen parameter calculated from the ultrasonic data for LY12Al are 430.97 K and 2 025, respectively.

Study on High Pressure Physical Properties of Diesel Oil

ZHANG Jian-Ming, ZHANG Wei-Gang, WANG Ya-Wei, WANG Xiao-Dong

2005, 19(1): 41-44 . doi: 10.11858/gywlxb.2005.01.008

PDF (811)

Abstract:
The physical properties of diesel oil are the base of simulating high pressure fuel injection system, where the pressure and temperature fluctuation are significant. The density, bulk modulus, kinematic viscosity and vapor pressure of diesel oil are studied by experiments in this paper, from which the density, bulk modulus and kinematic viscosity variations with the pressure and temperature are abstracted. The errors between the calculation data and tested data are less than 3%, and its correlation coefficients are higher than 0.998. The obtained experimental functions have satisfied the high precision requirement for simulation of the fuel injection system.

Magnetic Field and Temperature Effects on the Self-Trapping Energy of the 2-D Spin Magnetopolaron in an InAs Crystal

LI Zi-Jun, LI Gang

2005, 19(1): 45-50 . doi: 10.11858/gywlxb.2005.01.009

PDF (819)

Abstract:
Under the circumstances of magnetic field, high pressure and high temperature, the influence of the electron-spin on the self-trapping energy of the weak-coupling 2-D magnetopolaron was studied by using unitary transformations and the linear combination operator method. Numerical calculation, with InAs semiconductor as an example, illustrated that the self-trapping energy level of the weak-coupling 2-D magnetopolaron was divided into two by the electron-spin of different direction. The split self-trapping energy level was more marked with increasing magnetic field. The self-trapping energy of the magnetopolaron decreased and the ratio of electronspin energy to the self-trapping energy of the magnetopolaron increased with increasing magnetic field or temperature. The ratio of electron-spin energy to the self-trapping energy of the magnetopolaron was very large, when the magnetic field performed sufficient strong and the temperature performed sufficient high.

Deformation and Perforation of Simply-Supported Circular Plates Struck Normally by Flat-Faced Projectiles

Wen He-Ming, Rao Wei-Feng

2005, 19(1): 51-58 . doi: 10.11858/gywlxb.2005.01.010

PDF (732)

Abstract:
A previously proposed approximate quasi-static theoretical method is employed herein to examine the deformation and perforation of a simply-supported circular plate struck by a flat-faced projectile at normal incidence. Based on the principle of virtual work, static load-displacement relationships are first obtained and then used to predict the energy-absorbing capacity of the plate subjected to relatively low speed impact. It is shown that good agreement is obtained between the theoretical predictions and the available experimental data, provided that adiabatic shear plugging failure does not occur, but the influence of strain rate sensitivity is taken into account.

Analysis on the Influence of Multi-Layered Media on Stress Wave Propagation

DONG Yong-Xiang, HUANG Chen-Guang, DUAN Zhu-Ping

2005, 19(1): 59-65 . doi: 10.11858/gywlxb.2005.01.011

PDF (937)

Abstract:
The influence of multi-layered media on stress wave propagation characteristics has been analysed by the low velocity impact experiments and the corresponding numerical simulation. It shows that the wave amplitude and the actuation time are both affected by foamed materials in the layered media, and the energy absorption of multi-layered media with the foamed materials is obvious. As a result, the energy and momentum of different layer are changed when stress wave propagates in the layered media. Comparing the media including foamed aluminium with the media including foamed concrete, it has been shown that foamed concrete can lead to the lower wave amplitude, but foamed aluminium can absorb the more energy than that of foamed concrete under the condition of low velocity impacts.

Experimental Study on the Breaking of Rock by Ultra-High Pressure Water Jetting

FENG Yun-Chun, XU Yi-Ji, ZHAO Fu-Guo

2005, 19(1): 66-70 . doi: 10.11858/gywlxb.2005.01.012

PDF (855)

Abstract:
Ultra-high pressure water jetting has a use for assisting mechanical breaking of rock in petroleum drilling. We found by experiment that the main factors affecting the breaking of rock are pressure, distance, speed and angle of jetting. With the pressure increasing, the breaking of rock is better and at 150 MPa, the efficiency of rock breaking is the highest. The most distance of jetting is 32.5 times diameter of nozzle when the pressure is 200 MPa, and the best jetting angle is 12.5.

Expressions of Cold Specific Energy and Cold Pressure for Detonation Products

LI Yin-Cheng

2005, 19(1): 71-79 . doi: 10.11858/gywlxb.2005.01.013

PDF (1007)

Abstract:
The gas product of detonation of a secondary explosive can be described by a liquid equation of state that describes interaction between the molecules as strong repulsive and all outer heat motions of the molecule as free translations. The solid product carbon can be described as the rigid body. Then, a two-phase repulsive-translation equation of state of detonation product (two-phase R-T EOS for short) has been obtained. The two-phase R-T EOS using a known isentropic composed of two sections and through the CJ point as a reference curve has been named two-phase R-T (k, ) EOS and used to estimate the detonation and strong-detonation parameters of some explosives. The theory and experiment values of detonation parameters are in good agreement. The expressions of specific energy and pressure that describe strong repulsive interaction between molecules (cold specific energy and cold pressure for short) are necessary in order to estimate detonation temperature directly and conveniently. The expressions of cold specific energy and cold pressure with uncertain parameters A, m, n and l were obtained with reference to repulsive terms of the Mores and Mie potential expressions, then the two-phase R-T EOS characterized by the cold specific energy and the cold pressure was named two-phase R-T (A, m, n, l) EOS. With experimental {D, 0} data of TNT, the parameters n and l were determined, namely, n=1 and l=1/3, because the error between calculated and experimental data is minimum (0.59 %) in this case. The two-phase R-T (A, m, n, l) EOS of n=1 and l=1/3 was named two-phase R-T (A, m) EOS for short.A test of the two-phase R-T (A, m) EOS with the experimental parameters of strong detonation for Nitromethane was performed. The average error between calculated and experimental data of detonation velocity and temperature are respectively 0.36% and 203 K. The latter can be explained as without consideration of melting of graphite. Therefore a conclusion that the two-phase R-T (A, m) EOS is a proper equation of state of detonation product was obtained.

Measurement of Blowoff Impulse in Materials Radiated by Pulsed Soft X-Ray with a Pendulum Target System

PENG Chang-Xian, TAN Hong-Mei, LIN Peng, LI Hong-Jie, MENG Gang

2005, 19(1): 80-85 . doi: 10.11858/gywlxb.2005.01.014

PDF (823)

Abstract:
The blowoff impulse in materials radiated by the pulsed soft X-ray on Qiangguang-Ⅰ accelerater was measured by using an impulse equipment in which the target-pendulum moves in the rotational way. For a composite radiated at average energy of 0.21 keV, pulse width of 36 ns, and fluence of 143 J/cm2, the coupling coefficient of the blowoff impulse was measured as about 0.70 Pas/(Jcm-2).

Numerical Simulation of EFP Formation with Hemispherical Liner

PANG Yong, YU Chuan, GUI Yu-Lin

2005, 19(1): 86-92 . doi: 10.11858/gywlxb.2005.01.015

PDF (945)

Abstract:
The EFP formation with Hemispherical Liner is simulated using 2-D axisymmetric lagrangian code provided by LS-DYNA. The criterion of numerical method is discussed, and the typical processes of EFP formation, velocity and kinetic energy are studied. Differences between 6 models are analyzed, and the calculated results are in good agreement with the experimental observations.

Numerical Simulation and Experimental Study of Penetrator with Composite Structure Impacting Concrete Targets

WANG Ke-Hui, CHU Zhe, ZHOU Gang, WANG Jin-Hai, ZHU Yu-Rong, MIN Tao, HAN Juan-Ni

2005, 19(1): 93-96 . doi: 10.11858/gywlxb.2005.01.016

PDF (908)

Abstract:
In this paper, a kinetic penetrator with tandem warheads is designed. Numerical simulations and a series of size scaled experiments were conducted for the penetrator impacting semi-infinite concrete targets under different impact condition. The damage mechanism of the penetrator to target has been analyzed. Computational results and experimental results are in good agreement, which provides technical support for the design of penetrator impacting hard targets.

2005 Vol. 19, No. 1

Login in

NewsMore

LinksMore