Progress on Compounds of Inert Element Helium under High Pressure
TIAN Yifan, LIU Hanyu
2023, 37(3): 030101.
Crashworthiness Evaluation of Star-Shaped Hybrid Multi-Cell Tubes under Multiple Impact Angles
KONG Zhicheng, HU Jun, LIU Qiqi
2023, 37(3): 034204.
Analysis of Energy Characteristics and Failure Mode of Pegmatite Gabbro under Confining Pressure
LIU Haoshan, ZHANG Zhiyu, HUANG Yonghui, CHEN Chengzhi, MENG Jiale
2023, 37(3): 034103.
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
2023, 37(4)  
2023, 37(4): 1-2.  
Physical Property and Structure
Phase Transition Mechanism of Graphite to Nano-Polycrystalline Diamond Resolved by Molecular Dynamics Simulation
CHEN Guwen, XU Liang, ZHU Shengcai
2023, 37(4): 041101.   doi: 10.11858/gywlxb.20230663

Previous studies have found that the nano-polycrystalline diamond (NPD) is harder than single crystal diamond, consequently NPD prepared from graphite has been widely studied. Previous experiments revealed that the NPD originated from graphite contains both homogeneous fine structure and lamellar structure, while the mechanism has not been fully understood. In this work, molecular dynamics simulation was carried out, in which graphite models with different interlayer spacings were built up and compressed. The results showed that the graphite under different compression conditions exhibit different phase transition behaviors, namely, lamellar diamond is obtained under martensite transformation, and fine nanodiamonds without a specific orientation are obtained under diffusive transformation. Under hydrostatic pressure, or, if the slip of the graphite layer is not limited and [002] is the maximum pressure direction, the graphite converts into lamellar cubic diamond; if the maximum pressure is in [210] or [010] direction, the phase transition product is the polycrystalline diamond; if the maximum pressure is in [002] direction, the slip of graphite layers is hindered, the product is a mixture of polycrystalline hexagonal and cubic diamond. The microscopic analysis of atomic motion reveals the formation mechanism of NPD transformed from graphite with homogeneous fine structure and lamellar structure, which is expected to provide insights for large-scale synthesis of superhard NPD.

Density Generalized Function Theory Study on New MAX Phase M2SeC (M=Zr, Hf) under High Pressure
HE Xin, TIAN Hui, WANG Jian, CHEN Wanlei, WEI Zhaoxuan, LIU Jincheng, QI Dongli, SHEN Longhai
2023, 37(4): 041102.   doi: 10.11858/gywlxb.20230644

The effects of pressure on the crystal structure, elasticity, electronic and thermodynamic properties of the new MAX phases Zr2SeC and Hf2SeC were investigated by employing the first principle of density generalized function theory. Elastic constants and phonon calculations show that both compounds have stable structure in the pressure range of 0–40 GPa. Unlike most MAX phases, Zr2SeC and Hf2SeC are more easily compressed along the a-axis than along the c-axis, and the effect of external pressure on the crystal structure of Zr2SeC is more significant than Hf2SeC. Electronic structure calculations show that Zr2SeC and Hf2SeC have metallic properties, and the electronic density of states at the Fermi energy level decrease gradually with increasing pressure, thus improving the stability of Zr2SeC and Hf2SeC. In addition, the elastic modulus, the Poisson’s ratio and the anisotropy index show an enhancement with increasing pressure. In the pressure range of 0–40 GPa, the elastic modulus of Hf2SeC is greater than that of Zr2SeC at the same pressure, indicating that Hf2SeC has stronger resistance to fracture and deformation than Zr2SeC at high pressure. Thermodynamic property calculations show that Zr2SeC and Hf2SeC have higher melting temperatures in the pressure range of 0–40 GPa.

High Pressure Technology and Material Synthesis
Characterization and Performance of Nano-La2O3 Prepared by Detonation Method
ZHU Qunlong, WANG Quan, WANG Xuguang, LI Rui, TU Changchang, YANG Rui, ZHU Wenyan
2023, 37(4): 043201.   doi: 10.11858/gywlxb.20230643

It is very important that new preparation method of nano-lanthanum oxide is explored in view of the current problems of low purity, poor sinterability, and large molecular gaps. Detonation method was employed to prepare rare earth nano-La2O3 powder in this study. La(NO3)3·6H2O was added to the emulsion explosive as a lanthanum source, and the high temperature and high pressure conditions for the synthesis of La2O3 were provided by the detonation reaction of the emulsion explosive in a 0.5 kg TNT equivalent vacuum explosion container. The physical phases, morphologies and ingredients of the purified and forged products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and the powder performances were determined by ultraviolet-visible spectroscopy (UV-Vis), Brunauer Emmett Teller (BET), CO2-temperature programmed desorption (CO2-TPD) and O2-temperature programmed desorption (O2-TPD). The results show that the forging temperature has a significant effect on the crystalline growth of La2O3 powder. Nano-La2O3 powder with high ultraviolet light absorption, high purity and good dispersion was successfully produced at a forging temperature of 800 ℃ and a forging time of 3 h. The particle size is in the range of 50-175 nm, and the crystal has a hexagonal structure. The specific surface area of the nano-La2O3 is 17.46 m2/g, with a good pore order and concentrated pore size distribution. The nano-La2O3 has good adsorption of acid gas and oxygen migration performance. The detonation method applied to the preparation process of nano-La2O3 powder provides a new reference for the industrial preparation of nano-La2O3.

Measurement Performance Regulation of PVDF Sensor Based on Composite Piezoelectricity
XIE Lin, LIU Yingbin, FAN Zhiqiang, HU Xiaoyan
2023, 37(4): 043401.   doi: 10.11858/gywlxb.20230645

To explore the flexible measurement technology under low-intensity shock wave, the shock tube calibration experiment was carried out for the polyvinylidene difluoride (PVDF) sensor based on the flexible substrate with an aperture of 8 mm. According to the experimental results, different bonding modes are used to add different thicknesses of damping layer for the PVDF sensor, and the reliability of the sensor was evaluated in terms of the signal pulse width, the sensitivity coefficient and the amplitude of overshoot signal after loading shock waves with different intensities. Then the narrow pulse width shock wave was loaded to verify that the designed sensor can adapt to the measurement of different pulse width shock waves. The experimental results show that adding damping layer can greatly reduce the amplitude of overshot signal and improve the pulse width and frequency response of sensor measurement. STS-400 (single-side thickened sensor-400) under two types of pulse width signal loading obtained better test results, and the relative measurement error is not greater than ±12%. At the same time, it is concluded that PVDF film sensor is more suitable for testing signals with a pulse width of 10 ms or less. The new PVDF sensor designed can provide ideas for measuring explosive shock wave signals.

Dynamic Response of Matter
Dynamic Tensile Properties and Failure Mechanism of Glass Fiber Reinforced Polycarbonate Composite
GUAN Hailu, ZHANG Xiaoqiong, SHU Hongji, WANG Zhihua
2023, 37(4): 044101.   doi: 10.11858/gywlxb.20230648

In order to investigate the tensile mechanical behavior and failure mechanism of polycarbonate (PC) composite reinforced by short glass fibers in different orientations at a wide range of strain rates, the tensile experiments of PC composites with 20% glass fiber content and fiber orientations of 0°, 45° and 90° were carried out at a strain rate range of 0.001-1000 s−1 by using a material test machine, a medium strain rate test machine, and a split Hopkinson tensile bar device. The fractured surface morphologies of the three types of specimens under the stain rate range of 0.001-1000 s−1 were analyzed with scanning electron microscopy. The experimental results showed that PC composites have significant strain rate effects on tensile propertie and failure mechanism. When the loading strain rate increases from 0.001 s−1 to 1000 s−1, the tensile strengths of the specimens contained 0°, 45° and 90° glass fibers are increased by 57.5%, 58.2% and 49.4%, respectively, while the failure strains are increased by 74.1%, 125.1% and 129.1%, respectively. The tensile strength of specimen with glass fiber orientation of 0° is higher than that of the other two types of specimen, while the failure strain is lower than that of the other two types of specimen. Under the strain rate of 0.001 s−1 in quasi-static loading, there are four failure modes of the glass fiber reinforced PC composites: fiber pull-out, fiber fracture, matrix brittle fracture and fiber/matrix debonding. At the high strain rate of 1000 s−1, there are five failure modes: fiber pull-out, fiber fracture, matrix plastic deformation, matrix plastic fracture, and fiber/matrix debonding. The adiabatic temperature rise effect under high strain rate loading leads to a softening of the PC matrix in the glass fiber reinforced PC composite, resulting in a plastic deformation and an increase of matrix/fiber interface adhesion force, which is the main mechanism of the significant increase of the failure strength and failure strain compared with that under quasi-static loading.

Design and Mechanical Properties of Short Carbon Fiber Reinforced Biomimetic Materials
YANG Zhengqing, LUAN Yunbo, ZHANG Juqi, WEN Zhen, WANG Wei, LI Mingzhen, LI Yongcun
2023, 37(4): 044102.   doi: 10.11858/gywlxb.20230639

In natural evolution, numerous biomaterials exhibit astonishing mechanical properties due to the exquisite coordination of their internal structures at all levels. Carbon fiber, as an excellent artificial material, provides an important raw material support for the design of biomimetic materials. This study uses short carbon fibers and polyurethane as raw materials, combined with a syringe extrusion and thermal evaporation methods to prepare short carbon fiber reinforced polyurethane composite film with specific fiber orientation. Then, a spiral layered structure material resembling mantis shrimp with different interlayer angles was prepared using laminated assembly method. In addition, the mechanical strengthening mechanism of the material was studied by observing its morphology characteristics before and after stretching and measuring its tensile strength. The results show that short carbon fibers have good orientation consistency in thin film materials. When the fiber orientation angle is 45°, the tensile strength of the thin film material is the highest; when the interlayer angle is 30°, the tensile strength of short carbon fiber reinforced polyurethane biomimetic spiral structure material is the highest. The results of this study are of guiding significance for the design and preparation of high-performance short fiber reinforced composite materials, and for achieving their performance biomimetic optimization.

Quasi-Static Compression Stability and Enegy Absorption Performance of Cellular I-Beam
TIAN Xinyu, DENG Qingtian, LI Xinbo, SONG Xueli, WANG Guosheng, WEN Jinpeng
2023, 37(4): 044103.   doi: 10.11858/gywlxb.20230657

Lightweight cellular I-beams have excellent energy absorption characteristics under external loads. This paper proposes to use cell web instead of solid web to design the I-beam structure of cell web. Based on the combination of square cell, honeycomb cell, concave cell and round cell, and square, honeycomb, concave and circular web openings, the configuration of this paper was designed. The effects of different sibling type and web opening type on compression performance and energy absorption of I-beam were studied by experiments and finite element analysis. The results show that cell types and web hole types have significant effects on the compression performance of I-beam. The ultimate bearing capacity of square cell I-beam is larger, while honeycomb cell I-beam has the best energy absorption characteristics, while circular cell I-beam has poor bearing capacity and energy absorption performance. The negative Poisson’s ratio cell can significantly change the deformation mode of thin-walled I-beam, and the concave cell can effectively inhibit the dislocation extrusion instability trend of I-beam on both sides of the web.

Energy Absorption Characteristics of Circular Nested HierarchicalMulti-Cell Tubes under Axial Impact
HUANG Cuiping, DENG Xiaolin
2023, 37(4): 044104.   doi: 10.11858/gywlxb.20230619

Combining hierarchy with nested, two kinds of circular nested hierarchical multi-cell tubes with different nested methods were designed innovatively. The energy absorption characteristics under axial impact were studied by numerical simulation. The results show that the high-level multi-cell tubes have better energy absorption capacity than the low-level multi-cell tubes, regardless of the same wall thickness or the same mass. Under the same wall thickness, the specific energy absorption and crush force efficiency of high-level multi-cell tubes increased by 22.49% and 16.55%, respectively. Compared with the traditional circular tube, the specific energy absorption and impact efficiency of the multicellular tube were 43.16% and 36.45% higher, respectively. Under the same mass condition, the specific energy absorption and crush force efficiency of high-level multi-cell tubes were increased by 21.04% and 24.47%, respectively. Finally, the crashworthiness of circular nested hierarchical multi-cell tubes was studied systematically by the by used structural parameters such as layer number and wall thickness.

Numerical Simulation Study on the Influence of Hard Phase Shape on the Fracture Behavior of Ti-Al3Ti Bionic Composites
XIU Chengdong, WANG Changfeng, LI Bing, GUAN Renguo
2023, 37(4): 044201.   doi: 10.11858/gywlxb.20230629

Al3Ti is characterized by low density and high hardness, however, due to its brittleness, it is prone to fracture under smaller deformation. To improve the application range of Al3Ti, inspired by biological structures, a biomimetic finite element model was established based on the geometry of shell pearl layer, conch shell and fish scale, and the influences of hard phase shape, as well as impact velocity, were investigated to analyze the fracture resistance mechanism of bionic composites in terms of fracture behavior, crack propagation process and energy absorption effect. A shape coefficient was defined to optimize the structure design. The results show that the shape of the hard phase has a significant effect on the fracture behavior of the bioinspired pearl-like layer specimens under quasi-static condition. The rectangular hard phase can better hinder the crack growth toward the load end, thus improving the load-bearing capacity of the specimen. The specimen with shape factor around 5.0 shows the optimal fracture resistance and energy absorption. Under dynamic impact conditions, the soft phase has increased ability to hinder crack growth, which further improves the fracture resistance and energy absorption effect of the rectangular specimen.

Dynamic Response and Multi-Objective Optimization of Aluminum Foam-Filled Sandwich Tube under Lateral Blast Loading
WU Yupeng, ZHANG Tianhui, LIU Zhifang, LEI Jianyin, LI Shiqiang
2023, 37(4): 044202.   doi: 10.11858/gywlxb.20230634

​The dynamic response of aluminum foam-filled sandwich tubes subjected to lateral blast loading was investigated numerically using the dynamic explicit finite element method. Based on numerical simulation, the structural blast resistance was optimized with the core energy absorption and outer tube stiffness as the optimization objectives. The effects of structural geometric parameters, the relative density of the aluminum foam core layer, and blast loading conditions on the deformation patterns and energy absorption properties of aluminum foam-filled sandwich tube have been systematically investigated. The study results indicate that the deformation region of the aluminum foam-filled sandwich tube under lateral blast loading is mainly concentrated in the middle span. Energy absorption occurs through plastic deformation in the middle of the span and bending deformation at the left and right ends of the deformed region for both the inner and outer tubes. In contrast, the energy absorption of the aluminum foam core layer relies primarily on core compression. Reducing of the thickness of the outer tube or the relative density of the aluminum foam core layer can effectively improve the specific energy absorption of the structure and increase the deformation of the inner and outer tubes. The effect of the geometry parameters of the outer tube on the energy absorption properties of the structure and the deformation of the inner and outer tubes is much larger than that of the inner tube. A response surface model is constructed based on the numerical simulation results of aluminum foam-filled sandwich tube. Subsequently, multi-objective optimization is performed and the resulting Pareto front graph is provided. The determination of the wall thickness of the inner and outer tubes, together with the relative density of the aluminum foam core layers in the aluminum foam-filled sandwich tube, can be based on the specific engineering application requirements.

Dynamic Response of Equipment Cabin Bottom Plate of High-Speed Train Subjected to Ballast Impact
LU Kewei, JING Lin
2023, 37(4): 044203.   doi: 10.11858/gywlxb.20230642

Considering the real irregular geometrical characteristics of ballast and strain rate effect and failure behavior of material, finite element models of ballast impact on equipment cabin bottom plate of high-speed trains was established, and the deflection history response of transverse and longitudinal centerline nodes of equipment cabin front face sheet was analyzed. The history evolution regulation of contact force between equipment cabin bottom plate and ballast was investigated, and the effects of impact velocity, impact angle and ballast shape on impact response and damage behavior of equipment cabin bottom plate were also discussed, the failure mode and damage morphology characteristics of equipment cabin bottom plate under different conditions were analyzed, the relationship between the maximum transient deformation displacement as well as pit depth and impact velocity were quantified. The results show that, under the same impact condition, the maximum transient deformation displacement and pit depth of equipment cabin bottom plate increase with the increase of impact velocity and impact angle separately; the shape and size of maximum deformation zone of front face sheet of equipment cabin, and the area and distribution characteristics of front face sheet damage failure region are closely related to ballast shapes, the most severe damage failure occurs in ellipsoid ballast conditions; equipment cabin bottom plate under different impact conditions shows different degrees of ductile damage, and the larger ballast mass and impact velocity conditions also show tensile tear damage or even slight punching plug phenomenon.

Simulation Analysis of Mesoscale Characteristics in the Dynamic Fracture Damage of Heterogeneous Rock
CUI Niansheng, WEI Jianlin, YUAN Zengsen, XU Zhenyang, LIU Xin, WANG Xuesong
2023, 37(4): 044204.   doi: 10.11858/gywlxb.20230638

In order to investigate the mesoscale development in the dynamic fracture damage of heterogeneous rocks at the mineral crystal scale, a heterogeneous rock model that can reflect the microstructure characteristics was constructed based on the particle flow code-grain based model (PFC-GBM) method. By establishing the split Hopkinson pressure bar (SHPB) system using finite difference method FLAC2D and discrete element method PFC2D, the dynamic impact failure process of heterogeneous rock under different impact loading was simulated and studied. Through the self-compiled Fish language, the number of intragranular and intergranular microcracks in different minerals during the dynamic failure process was grouped and counted. The microscopic evolution process of dynamic fracture damage of heterogeneous rocks was deeply analyzed from a mesoscopic perspective. The research results show that intergranular failure is an important reason for the failure of the dominant heterogeneous rock under the static uniaxial compression condition. Under impact loading condition, the growth process of microcracks within and between crystals of each mineral had four stages: initiation, rapid growth, slow growth and stop growth. Similar to the growth pattern of the number of microcracks under static uniaxial compression condition, the number of intergranular cracks at the initial stage of dynamic failure was significantly higher than the number of intragranular cracks in each mineral. The rock mainly suffered intergranular damage. As the degree increases, the number of intragranular cracks in dynamic failure gradually exceeds the number of intergranular cracks. In addition, the peak strain rate and the corresponding maximum pressure as well as the dynamic peak strength and the corresponding maximum pressure under different impact loads in the simulation show good linear relationships, which provides a simple method to quickly determine the relevant dynamic mechanical parameters of the rock.

Molecular Dynamics Study on Impact Resistance of Ag-PMMA Composite Films
LIN Gaojian, GAO Wenpeng, CHEN Pengwan, SUN Weifu
2023, 37(4): 044205.   doi: 10.11858/gywlxb.20230655

It is very important for semiconductor manufacturing and small particle protection to study the dynamic impact response of nano-scale multi-layer composite structures. Molecular dynamics simulation was used to investigate the impact resistance of Ag-PMMA composite films supported with Si substrates in this paper. The energy dissipation mechanism of the metal polymer composite film supported on the substrate was explored through contact force response, kinetic energy loss, stress wave propagation, dislocation and damage evolution, and penetration depth. The results show that the impact process includes local compression stage and global deformation stage. During the local compression stage, the atoms in the contact region of Ag surface directly transform into amorphous structures due to the stress concentration effect under high-speed impact, so the contact force reaches the peak of the whole penetration process. The thickness of the film mainly affects the global deformation stage. The thinner composite film is obviously limited by the action of the substrate, and the penetrating damage occurs directly under the high-speed impact. However, the thicker composite film dissipates the kinetic energy of the bullet through a large number of Ag dislocations and PMMA elastic deformation, which can give full play to the material performance of each layer.

Quasi-Static Axial Energy Absorption Characteristics and Optimization of Sunflower-Like Sandwich Cylindrical Shells
NIU Lingeng, YAN Dong, WANG Genwei, SONG Hui, GUO Meiqing
2023, 37(4): 044206.   doi: 10.11858/gywlxb.20230637

Experiments, theoretical analysis, and numerical simulations were conducted to investigate the energy absorption characteristics of sunflower-like sandwich cylindrical shells under quasi-static axial loading. Firstly, quasi-static axial compression experiments and numerical simulations were conducted for sandwich cylindrical shells with three inner diameters and for their components. It was found that the specific energy absorptions and crushing force efficiencies of all sandwich cylindrical shells are greater than those of their individual components, and those of the sums of the individual components. The combination of cylindrical shell and corrugated core shell can effectively improve the energy absorption efficiency of thin-walled metal structure. Then, the theoretical formula of the axial average crushing force for the sandwich cylindrical shell was derived based on the simplified super folding element theory. The axial average crushing force predicted by the theoretical model was compared with the experimental and simulation results. It was found that the errors are within 10%. Finally, a multi-objective optimization design, with the objectives of maximum specific energy absorption and minimum peak crushing force for the sunflower-like sandwich cylindrical shell, was carried out. The Pareto front of specific energy absorption and peak crushing force of the sandwich cylindrical shell was obtained. The optimized sandwich cylindrical shell structure was improved in terms of specific energy absorption, average crushing force, and mass.

Influence of Interfacial Transition Zone on Crack Propagation Process in Concrete
JIA Shixu, ZHAO Tingting, WU Pei, LI Zhiqiang, WANG Zhiyong
2023, 37(4): 044207.   doi: 10.11858/gywlxb.20230606

Concrete is a heterogeneous composite material composed of coarse aggregate, mortar and interfacial transition zone (ITZ). ITZ is the weakest phase inside the concrete and has a significant effect on the macroscopic fracture process of concrete. To respectively explore the effects of the distribution and value of ITZ strength on the crack propagation process in concrete under uniaxial compression, a discrete element model that reflects complex mesostructures of concrete aggregate, mortar and ITZ is established in PFC 2D by the use of FISH code. The numerical simulation results showed that cracks follow the propagation order from the centre of concrete to the loading end during the crack propagation process, and more than 80% of cracks appear in the softening stage after peak stress. The ITZ strength distribution has a weak effect on the crack propagation process in concrete, and the number of cracks in concrete is large when the ITZ strength shows a U shape distribution. The decrease in ITZ strength value leads to a gradual increase in the number and range of cracks. When the ratio of the minimum bond strength of ITZ to the bond strength of mortar p<0.5, the concrete strength is significantly reduced and the cracks expand around the centre of the concrete model to form a network macro-crack, resulting in scattered fracture failure. When p>0.6, the cracks expand from the centre of the concrete specimen to the loading end to form a macroscopic penetration crack, resulting in block fracture failure.

High Pressure Applications
Optimization Design of Gas-Liquid Conveying Pipe Structure for 20 L Spherical Explosion Experimental Device
LI Feng, ZHANG Chenyu, WANG Yue, WANG Bo, ZHANG Mengyu, JING Yadong
2023, 37(4): 045301.   doi: 10.11858/gywlxb.20230651

The paper takes the gas-liquid conveying pipe section in a 20 L spherical explosive device as the research object. The flow pattern structure and cross-section air voids characteristics of gas-liquid two-phase flow in the gas-liquid conveying pipe were studied by numerical simulation. The curvature radius and horizontal pipe length of the gas-liquid conveying pipe section were optimized and designed based on the simulation. The results show that C6H14, C7H16, C8H18, and C10H22 can form stable annular flow under at pressure of 0.6 MPa. The flow structure of C6H14 and C7H16 tends to become unstable with increasing pressure. Under the pressure conditions of 0.6–0.9 MPa, when the curvature radius of the gas-liquid conveying pipeline section is 34 mm and the length of the pipeline section is 200–300 mm, most of the liquid phase forms a film and moves along the pipeline wall, and the distribution of the liquid film is relatively homogeneous. The gas phase located in the center of the pipe section flows at high speed with a good gas core. It forms a more stable annular flow pattern structure. The optimization design of the gas-liquid conveying pipeline section can make the measurement of explosion characteristics more accurate, and provide a reference for the study of combustible liquid fuel explosion problems and engineering design.

Experimental Study of the Effect of Shear Stress on Phase Transition in c-Axis CdS Single Crystal under Dynamic Loading
TANG Zhi-Ping, Gupta Y M
1989, 3(4): 290-297 .   doi: 10.11858/gywlxb.1989.04.005
[Abstract](13457) [PDF 8643KB](2188)
For a long time, the problem whether shear stress affects the phase transition initial pressure is not well solved. Duvall and Graham suggested that cadmium sulfide (CdS) crystal could be used to study the effect of shear stress on the initial pressure of phase transition in c-axis CdS single crystal specimens under high velocity impact systematically. The axial stress of initial phase transition measured is T=(3.250.1) GPa, corresponding to a mean pressure pT=(2.290.07) GPa, which agrees the value 2.3 GPa of static results quite well within the experimental error. The shear stress in this case, T=0.72 GPa, is as high as 31.5% of the mean pressure. This result shows that the mechanism of phase transition may be assumed only to relate to a critical mean pressure or critical thermodynamic state, and the effect of shear stress can be ignored.
Flattening of Cylindrical Shells under External Uniform Pressure at Creep
Shesterikov S A, Lokochtchenko A M
1992, 6(4): 247-253 .   doi: 10.11858/gywlxb.1992.04.002
[Abstract](9415) [PDF 2836KB](1954)
Experimental studies of the deformation of cylindrical shells under creep to fracture conditions are described in this paper. Analyses of three series of test shells are given and experimental and theoretical results are compared with each other.
The Generation of 90 GPa Quasi-Hydrostatic Pressures and the Measurements of Pressure Distribution
LIU Zhen-Xian, CUI Qi-Liang, ZOU Guang-Tian
1989, 3(4): 284-289 .   doi: 10.11858/gywlxb.1989.04.004
[Abstract](15274) [PDF 6073KB](2601)
Quasi-hydrostatic pressures up to 90 GPa were obtained at room temperature in the diamond cell by using solid argon as pressure medium. The pressure distribution was determined by measuring the special shift of the R1 line of ruby at different positions within the sample chamber. Experimental results showed that the pressure differences (p) between the pressures at each point within the chamber and the mean pressure (p) were very small, ratios of p/p were less than 1.5% when below 80 GPa. The shape of ruby R lines at 90 GPa is similar to that at ambient pressure. Thus, quasi-hydrostatic pressure near 100 GPa can be obtained by using solid argon as pressure medium. Moreover, the red shifts with pressures of the peak positions at 14 938 and 14 431 cm-1 in ruby emission spectra, were also examined. It concluded that the line, 14 938 cm-1, can be adopted in the pressure calibration.
A Study on Calculation of the Linear Thermal Expansion Coefficients of Metals
ZHENG Wei-Tao, DING Tao, ZHONG Feng-Lan, ZHANG Jian-Min, ZHANG Rui-Lin
1994, 8(4): 302-305 .   doi: 10.11858/gywlxb.1994.04.010
[Abstract](15875) [PDF 1350KB](1088)
Based on the expression of pressure at temperature T and in terms of the universal equation of state Debye model and the thermodynamic relations, a general expression for the calculation of the linear thermal expansion coefficients of metals is obtained. This formula applied to the calculation of Al, Cu, Pb. Calculated results are in good agreement with the experiments.
Development of Large Volume-High Static Pressure Techniques Based on the Hinge-Type Cubic Presses
WANG Hai-Kuo, HE Duan-Wei, XU Chao, GUAN Jun-Wei, WANG Wen-Dan, KOU Zi-Li, PENG Fang
2013, 27(5): 633-661.   doi: 10.11858/gywlxb.2013.05.001
[Abstract](13950) [PDF 12118KB](956)
The large volume press (LVP) becomes more and more popular with the scientific and technological workers in the high pressure area, because it could generate relatively higher pressure, provide better hydrostatic pressure and could be utilized in conjunction with in situ X-ray diffraction, neutron diffraction and ultrasonic measurement. There have been generally two LVP techniques to generate high-pressure: the double-anvil apparatus and the multi-anvil apparatus (MAA). Hinge-type cubic presses, as the main apparatus in china, have been widely used in the fields of both scientific research and diamond industry. However, for a long time past, the maximum pressure using the conventional one-stage anvil system for hinge-type cubic press is about 6 GPa, and the techniques about two-stage apparatus (octahedral press) that could generate pressure exceed 20 GPa is blank in our country. To a certain extent, the backwardness of the LVP technology in china restricts the development of high pressure science and related subjects. In recent years, we designed two kinds of one-stage high pressure apparatus and the two-stage apparatus based on hinge-type cubic-anvil press, the one-stage high pressure apparatus and the two-stage apparatus using cemented carbide as anvils could generate pressures up to about 9 GPa and 20 GPa respectively. This article mainly reviews the mechanics structure, design of cell assembly, pressure and temperature calibration, design and preparation of the sintered diamond anvils and pressure calibration to 35 GPa using sintered diamond as two-stage anvils about the one-stage high pressure apparatus and the two-stage apparatus designed in our laboratory.
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
[Abstract](8197) [PDF 1765KB](279)
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.
The Failure Strength Parameters of HJC and RHT Concrete Constitutive Models
ZHANG Ruo-Qi, DING Yu-Qing, TANG Wen-Hui, RAN Xian-Wen
2011, 25(1): 15-22 .   doi: 10.11858/gywlxb.2011.01.003
[Abstract](17027) [PDF 689KB](958)
The analyzed and calculated results indicate that the concrete failure strength will decrease under higher hydrostatic pressure, when the original failure parameters of HJC and RHT models implemented in LS-DYNA and AUTODYN are adopted. A new method is introduced which using the characteristic strength of concrete to confirm the modified failure parameters of HJC and RHT models. The same physical experiment of concrete penetration was simulated using the modified HJC and RHT failure parameters respectively, and the numerical results demonstrated that the RHT model matched the experiments much better. But the numerical results with the HJC modified failure parameters were not enough satisfied, because the third invariant of the deviated stress tensor was not considered in the HJC model.
Modification of Tuler-Butcher Model with Damage Influence
JIANG Dong, LI Yong-Chi, GUO Yang
2009, 23(4): 271-276 .   doi: 10.11858/gywlxb.2009.04.006
[Abstract](10607) [PDF 402KB](758)
A modificatin of Tuler-Butcher model including damage influence was presented, which was incorporated into a hydrodynamic one-dimensional finite difference computer code, to simulate the process of spall fracture of 45 steel and Al-Li alloy. The calculated results are in good agreement with experimental data, and shows the correctness of the model.
Recent Progresses in Some Fields of High-Pressure Physics Relevant to Earth Sciences Achieved by Chinese Scientists
LIU Xi, DAI Li-Dong, DENG Li-Wei, FAN Da-Wei, LIU Qiong, NI Huai-Wei, SUN Qiang, WU Xiang, YANG Xiao-Zhi, ZHAI Shuang-Meng, ZHANG Bao-Hua, ZHANG Li, LI He-Ping
2017, 31(6): 657-681.   doi: 10.11858/gywlxb.2017.06.001
[Abstract](10803) [FullText HTML](4629) [PDF 2527KB](4629)

In the last 10 years or so, nearly all major Chinese universities, schools and research institutes with strong Earth science programs showed strong interest in developing a new research branch of High-Pressure Earth Sciences.As a result, many young Chinese scientists with good training from the universities in the west countries were recruited.This directly led to a fast growing period of about 10 years for the Chinese high-pressure mineral physics research field.Here we take the advantage of celebrating the 30th anniversary of launching the Chinese Journal of High Pressure Physics, and present a brief summary of the new accomplishments made by the Chinese scientists in the fields of high-pressure mineral physics relevant to Earth sciences.The research fields include:(1) phase transitions in the lower mantle; (2) high spin-low spin transitions of iron in lower mantle minerals; (3) physical properties of the Earth core; (4) electrical measurements of rocks; (5) electrical measurements of minerals; (6) elasticity of minerals (especially equation of states); (7) high-pressure spectroscopic studies; (8) chemical diffusions in minerals; (9) ultrasonic measurements under high pressure; (10) physical properties of silicate melts; (11) geological fluids.In sum, the last 10 years have seen a rapid development of the Chinese high-pressure mineral physics, with the number of scientific papers increasing enormously and the impact of the scientific findings enhancing significantly.With this good start, the next 10 years will be critical and require all Chinese scientists in the research field to play active roles in their scientific activities, if a higher and advanced level is the goal for the Chinese mineral physics community.

Experiment and Numerical Simulation of Cylindrical Explosive Isostatic Pressing
CHEN Lang, LU Jian-Ying, ZHANG Ming, HAN Chao, FENG Chang-Gen
2008, 22(2): 113-117 .   doi: 10.11858/gywlxb.2008.02.001
[Abstract](13483) [PDF 1180KB](793)
The experiments of cylindrical explosive isostatic pressing were carried out. The internal temperatures in pressed explosives were measured by thermocouples. A thermal/structural coupled model of the explosive isostatic pressing was set up. The numerical simulations of cylindrical explosive were conducted. The calculated pressures and temperatures in explosives were given. The deformations,pressures and temperatures distribution were analyzed. The calculated results indicated that each surface center of the cylindrical explosive was sunken by isostatic pressing. During the isostatic pressing of cylindrical explosive, the internal temperature of the explosives increases, and the temperature and pressure are not uniform.
Perimeter-Area Relation of Fractal Island
1990, 4(4): 259-262 .   doi: 10.11858/gywlxb.1990.04.004
[Abstract](15590) [PDF 1508KB](2329)
The relationship of perimeter with area (P/A relation) of fractal island is discussed. It is shown that Mandelbrot's fractal relation between Koch perimeter and area does not hold in the island with finite self-similar generations. This might be the reason why the fractal dimension measured with P/A relation varied with the length of yardstick in previous work.
Long-Distance Flight Performances of Spherical Fragments
TAN Duo-Wang, WEN Dian-Ying, ZHANG Zhong-Bin, YU Chuan, XIE Pan-Hai
2002, 16(4): 271-275 .   doi: 10.11858/gywlxb.2002.04.006
[Abstract](14106) [PDF 2450KB](862)
Using two-stage light gas gun and laser technique for velocity easurement, we studied the long-distance flight performances of spherical fragments with different materials and different diameters. The flight distance is 60~120 m, and the initial velocity is 1.2~2.2 km/s. The experimental results show that: (1) the velocity attenuation coefficient of spherical fragment is constant, and (2) the air drag coefficient is slightly affected by the initial velocity of spherical fragment, the air drag coefficient is a linear function of initial velocity.
Factors Analysis of Debris Cloud's Shape of Hypervelocity Impact
TANG Mi, BAI Jing-Song, LI Ping, ZHANG Zhan-Ji
2007, 21(4): 425-432 .   doi: 10.11858/gywlxb.2007.04.016
[Abstract](13228) [PDF 1599KB](704)
The numerical simulations of hypervelocity impact of Al-spheres on bumper at normal are carried out using the smoothed particle hydrodynamics (SPH) technique. The simulation results are compared with experimental results, and the simulated hole diameters of bumper and debris cloud are well consistent with experimental results. The effect of impact velocity, bumper thickness, projectile diameter, materials, shape of projectile, interval on produced debris cloud are further analyzed. Regarding the length and diameter as index, orthogonal design method is applied to analyze the primary and secondary relations on the debris cloud's index of the three factors, that is impact velocity, bumper thickness and projectile diameter. The results indicate that bumper thickness is the main influence factor of debris cloud's length while projectile diameter is the main influence factor of debris cloud's diameter.
Design of the Sample Assembly for Ultrasonic Measurement at High Pressure and 300 K in Six-Side Anvil Cell
WANG Qing-Song, WANG Zhi-Gang, BI Yan
2006, 20(3): 331-336 .   doi: 10.11858/gywlxb.2006.03.019
[Abstract](10730) [PDF 411KB](619)
We introduced briefly the principle of design of sample assembly for ultrasonic measurements at high pressure, and designed a new kind of sample assembly to measure the isothermal compression of Al and Cu at 300 K. Ideal quasi-hydrostatic loading was realized, and high-quality ultrasonic signals were obtained under high pressure. It was indicated that the design of sample assembly was reasonable. We analyzed in brief main uncertainty of ultrasonic measurement in six-side anvil cell at 300 K.
Detonation Shock Dynamics Calibration of JB-9014 Explosive at Ambient Temperature
TAN Duo-Wang, FANG Qing, ZHANG Guang-Sheng, HE Zhi
2009, 23(3): 161-166 .   doi: 10.11858/gywlxb.2009.03.001
[Abstract](14152) [PDF 794KB](795)
Detonation shock dynamics (DSD) is an approximation to the reactive Euler equations that allows numerically efficient tracking of curved detonation waves. The DSD parameters are the velocity curvature relation and the boundary angle. A computer code was developed to facilitate the calibration of these parameters for JB-9014 insensitive high explosive using the generalized optics model of DSD. Calibration data were obtained from measurements of the detonation velocities and fronts in JB-9014 rate sticks at ambient temperature, with diameters of 10~30 mm. The steady state detonation velocities and fronts predicted by these DSD parameters are in very good agreement with experiment.
Shock Wave Physics: The Coming Challenges and Exciting Opportunities in the New Century-Introduction of the 12th International Conference of Shock Compression of Condensed Matter (SCCM-2001)
GONG Zi-Zheng
2002, 16(2): 152-160 .   doi: 10.11858/gywlxb.2002.02.012
[Abstract](14073) [PDF 500KB](842)
The 12th Biennial International Conference of the APS Topical Group on Shock Compression of Condensed Matter (SCCM-2001) was introduced. Papers presented in SCCM-2001 were surveyed and the recent progresses on shock compression of condensed matter were retrospected. The basic paradigms and the great achievements of the physics and mechanics of condensed matter at high dynamic pressure and stress were surveyed and revaluated. The coming challenges and exciting opportunities of shock wave physics in the 21 century were prospected.
Design and Temperature Calibration for Heater Cell of Split-Sphere High Pressure Apparatus Based on the Hinge-Type Cubic-Anvil Press
CHEN Xiao-Fang, HE Duan-Wei, WANG Fu-Long, ZHANG Jian, LI Yong-Jun, FANG Lei-Ming, LEI Li, KOU Zi-Li
2009, 23(2): 98-104 .   doi: 10.11858/gywlxb.2009.02.004
[Abstract](14643) [PDF 4054KB](782)
A new type of heater cell for the split-sphere high pressure apparatus based on the hinge-type cubic-anvil press was reported. This heating apparatus has the advantages of being simple, low cost, fast temperature rising, good heat insulation, and the temperature signal can be easily extracted. Carbon tube was used as a heating element for side-heating in our experiments. The size of the sample in the cell can reach 3 mm in diameter, and 7 mm in height. The relationship between the heating electric power and cell temperature was calibrated with Pt6%Rh-Pt30%Rt thermocouples under different pressures. The experimental results indicate that the temperature can reach 1 700 ℃ under the oil hydraulic pressure of 40 MPa (cell pressure is about 10 GPa).The temperature can keep stable for more than 2 h under a fixed power.
The Constitutive Relationship between High Pressure-High Strain Rate and Low Pressure-High Strain Rate Experiment
CHEN Da-Nian, LIU Guo-Qing, YU Yu-Ying, WANG Huan-Ran, XIE Shu-Gang
2005, 19(3): 193-200 .   doi: 10.11858/gywlxb.2005.03.001
[Abstract](10657) [PDF 416KB](753)
It is indicated that the constitutive equations at high strain rates proposed by Johnson-Cook(J-C), Zerilli-Armstrong (Z-A) and Bodner-Parton (B-P) collapse the data of flow stress in compression, tension, torsion, and shear into simple curve with the scalar quatities 'effective' stress and 'effective' strain, however, the collapsed data of flow stress did not include the data in the planar shock wave tests. The SCG constitutive equation proposed by Steinberg et al for the planar shock wave tests is discussed, which describes the coupled high pressure and high strain rate effects on the plastic deformation of materials. Basing on the recent experiments at elevated temperatures and high strain rates and the shear strength measurements during shock loading, the flow stress for tungsten at high pressure and high strain rates is estimated with J-C and SCG constitutive equations, respectively. It is concluded that the J-C, Z-A and B-P constitutive equations may not be appropriate to describe the plastic behavior of materials at high pressure and high strain rates, comparing with SCG constitutive equation. It is emphasized that the physical background of the constitutive equation at high pressure and high strain rates is different from that at low pressure and high strain rates.
Phase Evolution of Zr-Based Bulk Metallic Glass Prepared by Shock-Wave Quenching under High Temperature and High Pressure
YANG Chao, CHEN Wei-Ping, ZHAN Zai-Ji, JIANG Jian-Zhong
2007, 21(3): 283-288 .   doi: 10.11858/gywlxb.2007.03.011
[Abstract](13876) [PDF 534KB](688)
Phase evolution (PH) of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) prepared by shock-wave quenching has been studied under high-temperature and high-pressure using in situ synchrotron radiation energy-dispersive X-ray diffraction. The results show that the primarily precipitated phase is Zr2Be17 at applied pressures, but the subsequent PH processes are different. The crystallization temperature increases with pressure, but with a sudden drop at about 6.0 GPa. Compared with experimental results of the BMG prepared by water quenching, it can be concluded that crystallization temperature of the BMGs prepared by shock-wave quenching and water quenching all drop at the same pressure region, at which their PHs are different from those of other pressures. The different PHs and the drop of crystallization temperature may be attributed to that the BMG possesses different atomic configuration at different pressures.
Explosive Shock Synthesis of Wurtzite Type Boron Nitride
TAN Hua, HAN Jun-Wan, WANG Xiao-Jiang, SU Lin-Xiang, LIU Li, LIU Jiang, CUI Ling
1991, 5(4): 241-253 .   doi: 10.11858/gywlxb.1991.04.001
[Abstract](11896) [PDF 4689KB](2135)
Reported in the paper are techniques of wurtzite type boron nitride (wBN) synthesis from graphite type BN (gBN) by means of shock compressions created via explosive detonation. Recovered samples after shock processing are treated with molten alkalis and hydrochloric acid. Despite that the domestic gBN materials we used are far inferior, both in the crystallinities and particle sizes, to those used in foreign countries for the purpose of shock synthesis of wBN, the yield of our wBN reaches 11 to 12 g per shot, with a convertion ratio over 50%; X-ray diffraction and x-ray fluorescence spectrometry analyses reveal that the total impurity content of this chemically extracted wurtzite type boron nitride product is less than 0.5%. Four different starting gBN from different manufacturers were used in the experiments to synthesis wBN under the same conditions of shock compressions. It is found that the yield of wBN is closely related to the crystallinity of the starting gBN materials. Specific area measurements and XRD analysis indicate that our wBN is a polycrystal super-fine powder material with average particle size of 0.1 m, which consists of many primary crystallites of 17.5 nm in dimension. Thermal stability of our wBN powder is characterized by the emergence of an exothermic peak in the atmospheric gas condition from DTA analysis. Initial temperature of this exothermic reaction is about 1 055 K and peak temperature 1 238 K.

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Hosted by:Topical Communitte of High Pressure,
Chinese Physical Society

Sponsored by:Institute of Fluid Physics,CAEP

Editor-in-Chief:ZOU Guangtian