Based on Liberman's statistical self-consistent field INFERNO mode, we calculated the equation of sate (EOS) and the Hugoniot of gold (Au) in a wide range of temperatures and densities. The electronic part of the EOS for Au was obtained by solving the self-consistent field Dirac equation at each density and temperature. In the same way, the 300 K isotherm of gold was obtained by modifying the Virial pressure and the ion part of the EOS was calculated by the free volume model. The cold pressure and Hugoniot were compared with the experimental data and other theoretical methods with the most satisfactory achieved. Our study shows that Liberman's INFERNO model can be used to calculate the EOS for gold in a wide range of temperatures and densities.

We investigated the high pressure infiltration sintering of coarse grained cemented carbide with low cobalt content, where WC-16%Co (mass fraction) substrate was used to provide cobalt. The initial WC powder was prepared with vacuum hydrogen reduction in order to isolate the oxygen impurity. This paper mainly studied the effects of such sintering conditions as pressure, temperature and sintering time on the properties of the sintered body, and a high hardness value was obtained by controlling the sintering process. The sintered WC-Co samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Vickers hardness tests. The scanning electron microscopy (SEM) analysis reveals that the WC grains in well sintered alloys are round in shape and the sintered WC-Co alloy with a cobalt content of 5.7% exhibits a high hardness value of 17.4 GPa.

Preparing carbon nanospheres by gaseous detonation using oxygen-benzene mixture as the reactants is a new method. The crystal composition, grain size and phase structure were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results indicate that the dimension distribution of the carbon nanospheres ranges from 30 to 50 nm. The grain size decreases as the oxygen content increases, but the grain dispersivity is improved and the agglomerate is reduced. At the same time, the initial concentration of the reactants has significant influence on the synthesis of nanomaterial prepared by gaseous detonation. Furthermore, the growth mechanism of carbon nanospheres by gaseous detonation was discussed.

A method was established for modeling the electrical explosive process of the micro metal foil based on reasonable simplification and a 1D code was developed to simulate the electrical explosive process of the micro metal foil. The numerical results agree well with the experimental data. Compared with the experimental results, the calculated exploding current and burst time are within a difference of 5%. The calculated results show that the pressure of the exploding product can reach about 2 GPa, the temperature of the exploding product can exceed 10 000 K, and the degree of ionization is over 40%. Using this numerical method, we obtained the minimum exploding threshold of the voltage, which is important for the design of the micro-foil switch, and which was validated by the experimental results.

Based on the Monte-Carlo method, the meso-structural model of plastic bonded explosives (PBX) was established considering the grain size and location in random distribution by the non-linear finite element method. The influence of the binder and the defect hole to ignition characteristics of PBX in meso-structural was analyzed under shock and ramp loading. The results show that the critical pressure to ignite explosive rises with the increase of the binder content under shock and ramp loading. Compared with the results under shock loading, the critical pressure to ignite explosive under ramp loading is improved with the increase of the binder content. Also, the critical pressure to ignite explosive falls under shock loading, and rises under ramp loading due to the defect holes.

As a new type of protective armor used to meet the needs of military transport vehicles for protection against projectiles of small kinetic energy, the porous plate can achieve the purpose of light-weight armor protection while ensuring the protective requirement. There has been little research on armor performance of ceramic porous plates at home and abroad. In this work, we simulated the process of KE-projectile penetrating AD95 ceramic plates with holes of different shapes (triangle, circle, square) using the FEM/SPH coupled algorithm based on LS-DYNA3D software. By calculating the protective coefficient of plates with holes of different shapes and comparing the residual velocity and kinetic energy of bullet, we optimized the porous plates to achieve the best protective performance and lightest weight. It was found that the elastic properties of plate with circular holes plate is the best. The FEM/SPH coupling algorithm can simulate the ceramic's cracking and splashing. Besides, the numerically simulated results are in good agreement with the experimental results.

The finite element software, ABAQUS, has been used to establish the simulation models in order to study the performance of 2A12 aluminum alloy targets (with a thickness of 2 mm) impacted by projectiles (with different boundary conditions), and the data of the targets' residual velocities and ballistic limit velocities have been obtained. Based on the simulation results, the influence of the boundary effect on the projectile target failure models and ballistic resistance property are analyzed. The results achieved on the basis of the numerical study show that the influence of the projectiles' boundary effect on the targets' residual velocities is very much limited, becoming almost negligible when the projectile's velocity is high. However, this effect on the targets' failure models is significantly great:the targets' whole deformation and crack extension are increasingly more and more obvious when impacted by vertical-projectiles, convex-projectiles, bevel-projectiles, and concave-projectiles. In addition, the initial velocity of the projectiles can also influence the structural deformations, the degree of which is related to the projectiles' boundary effect.

The 5083 aluminum alloy is widely used in engineering, and is inevitably subjected to a variety of different loadings, including strong dynamic loading such as impact and collision.Therefore it is necessary to study its mechanical properties under loading of a wide range of strain rates as well as its constitutive model.With this in view, firstly, an experimental study of the 5083 aluminum alloy was carried out at quasi-static, middle and high strain rates of tension and compression loading and the stress-strain curves of the wide strain rate were obtained.The experimental results show that in the strengthening stage, the tensile stress-strain curves are always lower than the compression stress-strain curves when the experimental condition is kept constant, so the phenomenon is explained by microscopic mechanism.Then, by introducing damage into our study, the effects of damage on the material's mechanical properties were considered under impact tensile loading.Based on the continuum mechanics and experimental results, the damage evolution equation was obtained.Finally, by improving the Johnson-Cook (JC) constitutive model and the existing damage evolution equation, the dynamic constitutive model considering the damage of the 5083 aluminum alloy was established.By comparing the experimental curves with the model curves, it was found that their fitting is good, showing that the proposed model has good applicability.Our research can serve as an effective scientific basis, an analytical model and necessary reference for the engineering application of the 5083 aluminum alloy.

In the present study, we developed a two-stage 6-8 type multianvil high pressure apparatus, which is capable of pressurizing centimeter-scale samples above 15 GPa.We also designed and tested the heater cell for the apparatus.The relationship between the heating power and the cell temperature was calibrated under different pressures.With the successful experiment of directing transformation of hexagonal boron nitride to cubic boron nitride, the pressure and temperature in the heater cell was demonstrated.The experimental results indicate that the assembly can run stably under a pressure above 14 GPa and at a temperature above 1 800 ℃ for a centimeter size sample.

Spacer shaped charge can effectively adjust the detonation wave to improve the jet penetration capability; asymmetric initiation may lead to eccentric jet deflection, speed reduction and other phenomena, which is called the eccentric initiation effect.In the actual production process, however, it is difficult to control the detonation point of the shaped charge warhead and the installation of the wave-shaper.The present work investigated the effect of the partition on the shaped charge jet under eccentric initiation by using a finite element software LS-DYNA with ALE algorithm, and compared the forms and velocity distributions of the shaped charge jet at different eccentric amounts with and without partition.The results show that the shaped charge with a separator amplifies the eccentric initiation effect, and the greater the eccentric amount, the more obvious the amplifying effect.

In this work the constraint function of concrete was regarded as the distribution load associated with the transverse load, and the yield response of projectiles under the compressive and bending load was studied using the free-free beam theory, with the main parameters of the impact of the asymmetric transverse load examined.It was found that the projectiles can be easily bent as a result of greater asymmetric mass loss, greater difference in static resistance between the grout and the aggregate, and sharper projectiles, and projectiles subjected to the transverse impact load can be considered as the response of the cantilever beam without an axial constraint.In addition, the diabasis of the plastic hinge and the formation process of the J-shaped trajectory was analysed.

In the present work we performed the first principles calculations based on the density functional theory and investigated the P42/mnm-Pnnm phase transition and the mechanical properties of SnO₂.For the exchange-correction energy we employed the generalized gradient approximation (GGA) in the Perdew, Burke and Ernzerhof (PBE) form.The elastic stiffness coefficients, c_ij, bulk modulus, shear modulus, Young modulus, Reuss modulus, Voigt modulus and anisotropy factor were calculated for two polymorphs of SnO₂:rutile and CaCl₂ structure.Our results for the structural parameters and elastic constants at the equilibrium phase are in good agreement with the available theoretical and experimental values.Using the enthalpy-pressure data, we observed the rutile to CaCl₂ structural phase transition under 11.06 GPa pressure.In the low index plane of two polymorphs' SnO₂, the most unstable and the possibility of slippage crystal planes was the {100} crystal planes of Pnnm structure, and the {001} crystal planes has the strongest binding force.The Vickers hardness calculated for the P42/mnm of SnO₂ was 10.49 GPa, and the Pnnm structure was 11.42 GPa.Because of the differences in the level of the structure symmetry, results from calculation show that the Debye temperature waverd in a small range for the utile structure but it had mutations in 8-10 GPa and showed a downward trend for the CaCl₂ structure.

In this work we obtained an analytic model CIM2 for the flow field of the reaction zone of condensed explosives in early-stage shock initiation using the characteristic line, the simplified equation of state and the simplified relationship between the material impedance and the shock impedance.By choosing a single form of the reaction rate with the dissipative term, we calculated the particle velocity at different depths of condensed explosives.The CIM2 model was improved by the new hypothesis of the reaction rates at different depths, and was applied to the calculation of PBX 9501.The results show that the improvement of CIM2 can slow down the energy transport after the shock, and that the improved CIM2 can give a more exact calculation of the particle velocity of the shock and crest, the time at which the crest arrives, and the curve of the particle velocity.

The dynamic analysis software ANSYS/LS-DYNA was used in combination with smoothed particle hydrodynamics (SPH) method to simulate the boundary effect in explosive cladding.The two-dimensional simulation results reproduced the phenomenon of metal jet and boundary effect and were consistent with the production practice of explosive cladding.The simulated results also revealed that the fracture of the flyer plate occurs before the collision.Therefore, it can be drawn that the boundary effect here is not due to the excessive energy at the edge area.It is valuable to investigate the boundary effect in explosive cladding with SPH method.