高压物理学报

Application of ALE Multi-Material Formulation for Blast Analysis of Glass Curtain Wall

DENG Rong-Bing, JIN Xian-Long, CHEN Jun, SHEN Jian-Qi, CHEN Xiang-Dong

2010, 24(2): 81-87 . doi: 10.11858/gywlxb.2010.02.001

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Abstract:
The multi-material arbitrary lagrangian-eulerian (ALE) formulation and the penalty-based coupling approach were applied to simulate the air explosion and the interaction between explosive blast and curtain wall in resistance test of curtain wall by using LS-DYNA software. The dynamic behavior of glass curtain wall under blast loading was analyzed. Including the brittle failure of glass material in the model, the damage regions of inner and outer glass were reappeared in the numerical simulation. The numerical results are in agreement with the experimental observations, which will provide an important reference for the blast resistance design and improvement of glass curtain wall.

Experimental Research on Underwater Explosion Energy Output of Explosive

MU Jin-Lei, ZHU Xi, LI Hai-Tao, HUANG Xiao-Ming

2010, 24(2): 88-92 . doi: 10.11858/gywlxb.2010.02.002

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Abstract:
In order to understand the energy output characteristics for underwater explosion of explosive, especially the decay law of shock wave energy along with the distance, the efficient shock wave energy per unit mass was researched. In traditional empirical formulas, it satisfies the similarity law. The underwater explosion experimental results show that the shock wave energy, bubble energy and total energy per unit mass of TNT explosive are all in agreement with the empirical results. By analyzing the experimental results, the trend line of the efficient shock wave energy per unit mass decayed with the scale distance was obtained. Compared with the empirical results, it is found that the efficient shock wave energy decays more rapidly in small charge experiment.

Perforation of Fully-Clamped Thick Metallic Plates Struck Normally by Conical-Nosed Projectiles

SUN Wei-Hai, WEN He-Ming

2010, 24(2): 93-101 . doi: 10.11858/gywlxb.2010.02.003

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Abstract:
Simple analytical equations are given to predict the perforation of fully-clamped thick metallic plates struck normally by rigid conical-nosed projectiles over a wide range of velocities based on the assumption that the deformation is localized and that the impact energy is dissipated only by penetration. It is further assumed that the mean pressure offered by the target materials to resist the projectiles consists of two parts: a quasi-static part due to the elastic-plastic deformation of the laminate materials and a dynamic part due to penetration velocity. Equations are obtained for the residual velocity and ballistic limit. It transpires that the present model predictions are in good agreement with available experimental data for thick metallic plates struck normally by conical-nosed projectiles.

Research on Deformation Shape of Deformable Warhead

GONG Bai-Lin, LU Fang-Yun, LI Xiang-Yu

2010, 24(2): 102-106 . doi: 10.11858/gywlxb.2010.02.004

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Abstract:
Basing on the detonation theory, the structure of the deformable warhead was simplified to be double layer cylindrical shells under the detonation. Plastic hinges were introduced into the loading section of the shell, which contacted with the deforming charge, and the deforming charge was divided into small segments accordingly. Loading and movement of these segments were analyzed. Deforming shape of the cylindrical shell under the loading with equal distribution was bulgy, and the displacement of shell segments was obtained. Deforming charge with different thickness, according to the displacement of the segment, was set up to realize the same displacement of the shell segments on the loading direction. The D-shape was achieved theoretically, and the shape of deforming charge was designed accordingly. Numerical simulation validated the feasibility of the designed plan. The results indicate that the deformable warhead with the new-designed deforming charge can realize the D-shape.

Experimental Study on Phase Transition and Spall Fracture in FeMnNi Alloy under Shock Pressure

LI Qing-Zhong, CHEN Yong-Tao, HU Hai-Bo, XU Yong-Bo

2010, 24(2): 107-112 . doi: 10.11858/gywlxb.2010.02.005

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Abstract:
By means of velocity interferometer system for any reflector (VISAR), X-ray diffraction (XRD) and scanning electron microscope (SEM), phase transition and spalling behavior of the FeMnNi alloy were studied through symmetric impact and reverse impact experiments. The FeMnNi alloy experiences a phase transformation when shocked to the pressure above 6.5 GPa. The FeMnNi alloy produces reverse phase transition and rarefaction shock wave when the pressure reduce to 4～5 GPa due to the rarefaction wave. By analyzing the interaction among plastic wave, phase transition wave, rarefaction wave and rarefaction shock wave, it was found that the FeMnNi alloy has a physical mechanism inducing the formation of spall behavior in symmetric impact experiments as the impact stress exceeds transition threshold.

Structural Stabilities and Optical Properties of BaX (X=S, Se and Te) under High Pressure

HAO Ai-Min, YANG Xiao-Cui, ZHAO Yu-Wei, LIU Xin, SONG Ai-Jun, ZHANG Wei-Guo, XIN Wei

2010, 24(2): 113-119 . doi: 10.11858/gywlxb.2010.02.006

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Abstract:
An investigation on the structural stabilities and optical properties of BaX (X=S, Se and Te) under high pressure was conducted using first-principles calculations based on density functional theory. The results show that the sequence of the pressure-induced phase transition of these compounds is from the NaCl-type (B1) to the CsCl-type (B2) structure. The structural transition pressure and the metallization pressure are 8.57 and 45.4 GPa for BaS, 7.44 and 36.5 GPa for BaSe, 5.67 and 16.7 GPa for BaTe, respectively. The calculation of the optical properties showed that almost all peaks of the imaginary part of dielectric constant (2) in the B1 and B2 structures shift towards high-energy region with increasing pressure (blue shift), and the static dielectric constant increases as the pressure increases.

Calculation of the Hugoniot of Silicon Rubber Foam

WANG Qing-Song

2010, 24(2): 120-124 . doi: 10.11858/gywlxb.2010.02.007

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Abstract:
Based on the pore collapse energy model, a new thermodynamic equation of state was derived to predict and describe the Hugoniot behavior of the silicon rubbers foam with different initial states. The model was tested on the silicon rubbers foam with initial densities of 0.52 g/cm3 and 0.92 g/cm3, respectively. Compared with the corresponding experimental data published previously, the results showed that this Hugoniot model can satisfactorily predict the Hugoniot behavior of silicon rubber foam.

Effects of 3 GPa Pressure Treatment on the Thermal Expansion of Cu-Zn Alloy

WANG Hai-Yan, LIU Lin, PENG Gui-Rong, LIU Jian-Hua

2010, 24(2): 125-128 . doi: 10.11858/gywlxb.2010.02.008

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Abstract:
The coefficients of thermal expansion of Cu-Zn alloy between 25～700 ℃, which was before and after 3 GPa high-pressure treatment, were measured by the DIL402C thermal expansion instrument. In addition, the metallurgical microscope, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to characterize the microstructures and phase transformation of the alloy. Based on the experimental results, the effects of high-pressure treatment on the thermal expansion of Cu-Zn alloy were investigated. The high-pressure treatment can obviously increase the thermal expansivity of Cu-Zn alloy and change the trend of the thermal expansion curve. At 535.14 ℃, the thermal expansion curve after the high-pressure treatment reaches its peak value, which is 49.48% larger than the untreated alloy.

The Effect of Dynamic High Pressure Microfluidization on the Activity of Papain

LIU Wei, ZHONG Ye-Jun, LIU Cheng-Mei, XIE Ming-Yong, GUAN Bin, YIN Man, WANG Qian, CHEN Ting-Ting

2010, 24(2): 129-135 . doi: 10.11858/gywlxb.2010.02.009

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Abstract:
The effect of dynamic high pressure microfluidization (DHPM) on the activity of papain had been investigated, and the molecular conformation changes of papain had been detected by fluorescence spectra. The results showed that after DHPM (120～180 MPa) treatment, the enzyme activity decreased in different degrees. The papain activity reduced to 90.04% after 180 MPa treatment. With the increasing of treatment pressure, the fluorescence emission peaks of papain, Tyr and Trp residues gradually red shifted from 334, 285 and 277.5 nm for untreated sample to 335.5, 285.5 and 278.5 nm for 140 MPa treated sample, and then returned to 334, 285 and 278 nm for 180 MPa treated sample, respectively. After 24 h placing at 0～4 ℃, papain activity further decreased and the fluorescence intensity of papain and Tyr residue showed oscillate (down, up and down), which indicated that DHPM treatment (120～180 MPa) changed the molecular conformation of papain visibly with low stability of the new formed conformation.

Inactivation Effects of Coprinus Comatus Inoculated with Bacterial Spores by High-Pressure Thermal Processing

WANG Biao-Shi, LI Bian-Sheng, ZENG Qing-Xiao, HUANG Juan, RUAN Zheng, LI Lin

2010, 24(2): 136-142 . doi: 10.11858/gywlxb.2010.02.010

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Abstract:
The combination effect of high hydrostatic pressure and moderate heat on the inactivation effects of coprinus comatus inoculated with bacterial spores was investigated. The results showed that two bacterial spores (Bacillus coagulans and Bacillus stearothermophilus) had a much higher resistance in coprinus comatus than in phosphate buffer solution. Moreover, Bacillus stearothermophilus spore had a much higher resistance than Bacillus coagulans spore at the same pressure and temperature. Survival data were modeled using the linear, Weibull and Log-logistic models to obtain relevant kinetic parameters. The mean square error and regression coefficient suggested that the Log-logistic model produced best fits to all survival curves, following by Weibull model, and the linear model was not adequate for describing these curves. The Log-logistic model could be used to forecast the inactivation curves of bacterial spores by the combination of high hydrostatic pressure and moderate heat.

Effects of High Pressure Treated Seeds on the Growth and Development of Watermelon

LI Yu-Ge, SU Lei, LI Suo-Ping, HONG Shi-Ming, LI Hai-Tao, ZHAO Xiao-Wei, HUO Zhi-Bang, LI Guo-Shen

2010, 24(2): 143-153 . doi: 10.11858/gywlxb.2010.02.011

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Abstract:
By using the statistical significance test of sample rate, t-test and one-way analysis of variance (ANOVA), the effects of high pressure treated seeds on the emergence rate, chlorophyll content, peroxide enzyme activity, morphology and structure of cotyledon, average weight per watermelon and sugar content were studied in detail. In experiments, different varieties of seeds, such as Jingyin21, Huapi88, Zhenban, Guomou, Jinmeihei, Jinxiaolan, Mimeilv and Ribengua, were pretreated with high nitrogen gas pressure of 26~28 MPa or high hydrostatic pressure of 50~150 MPa at room temperature. Then the growth characteristics and main nutrition components were observed, measured and recorded. Compared with untreated controls, the experimental results showed that the germination rate and the content of chlorophyll c were significantly (P0.05) or extremely significantly (P0.01) reduced, and the chlorophyll a content and the peroxidase activity were significantly (P0.05) augmented. Additionally, the effects of the high pressure on average weight per watermelon and sugar content were obviously different in different cultivars. For Ribengua (P0.001) and Jinxiaolan (P0.092), the average weight per watermelon were strongly influenced when the seeds were treated under high hydrastatic pressure; for Guomou (P0.064), the influence noted on the sugar content was obvious.

Experimental and Theoretical Investigation on Laser Supported Detonation Waves in Air

CHEN Lang, LU Jian-Ying, FENG Chang-Gen

2010, 24(2): 154-160 . doi: 10.11858/gywlxb.2010.02.012

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Abstract:
For investigating the formation mechanism and propagation characteristics of the laser supported detonation waves, an experiment was designed and conducted. The laser supported detonation waves were generated in air atmosphere by focusing a 10.6 m microsecond pulse from a CO2 laser. In the experiment, a solid target was set to make the laser supported detonation wave ignition more easily and locate the laser supported detonation wave. The optical emission from the gap switch of the laser discharge tube was used to trigger the shutter of the high-time resolution (ns) camera, which was used to visualize the growing and propagation of the laser supported detonation regime spark. Formation mechanism and propagation characteristics of the laser supported detonation waves were analyzed, meanwhile the pressure and temperature behind the detonation front were calculated employing C-J detonation theory. In the initial stage of the breakdown, the detonation spark is spherical and transforms into meteoric shape in later time. The head of the meteoric body is the high-brightness and high-temperature plasma absorption layer, and the tail is low-brightness and low-temperature plasma. The laser supported detonation wave travels along the laser light channel toward the laser source. The temperature of the laser supported detonation waves was estimated to be 107 K. The propagation speed was estimated to exceed 18 km/s in the initial stage of breakdown, and then exponential decays with time. The analysis indicated that laser supported detonation waves will transform into shock waves as the energy absorbed by the detonation front cannot sustain the propagation of the detonation waves.

2010 Vol. 24, No. 2

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