The effects of high pressure treatment on the compressive strength of aluminum bronze were investigated, based on the measurement of its compressive strength, the analysis of its phase composition, and the observation of its microstructure and fracture morphology by means of electronic universal testing machine, X-ray diffraction, optical microscope, transmission electron microscope (TEM), and scanning electron microscope (SEM). The results show that high pressure treatment is favorable to form fine-grained microstructures and can reduce the compressive strength of aluminum bronze, while the compressive strength of the aluminum bronze treated at 2 GPa and kept at 600 ℃ for 2 min is increased about by 34%, compared with the as-cast alloy.

A new measurement system for transient Raman spectroscopy under gas-gun loading and the Raman spectra of shocked benzene have been reported in this paper. The experimental results show that the Raman shifts of C-H stretching mode (3 061 cm^-1) are linearly dependent of shock pressure between 0.8 GPa and 3 GPa. The extrapolation of the present results agrees well with the published experimental data. It shows that the new measurement system has good stability and repeatability, and it is an effective method to study the structural changes at the molecular level of transparent and semi-transparent materials under dynamic loading conditions.

A transverse velocity interferometer system for any reflector (VISAR) has been developed by combination of a multipoint VISAR and a tri-probe device. One probe emits and receives laser, and the other two probes receive laser from different directions. The transverse and longitudinal velocities can be deduced from Doppler shift of laser received by the tri-probe. The transverse VISAR were applied to detonation driving wedge target experiments. Planar shock wave in a 10° wedge steel target was generated by plane-wave lens and T/Γ explosive. The free surface transverse velocities induced by oblique collision of shock wave were measured. The maximum measured longitudinal velocity is about 1 680 m/s, and the maximum measured transverse velocity is about 140 m/s. The uncertainty of the transverse velocity measurement was analyzed, and the uncertainty is estimated to be about 33 m/s in the experiments.

A hydraulic opposite anvil system (HAL-11) consisting of an inner anvil cell, a hydraulic loading system, and an alignment system, is developed for high pressure in-situ neutron diffraction. The inner anvil cell can be compatible with various anvils with different culet sizes and materials, such as WC, sapphire, SiC, and sintered polycrystalline diamond. A maximum load up to 500 kN can be provided by the hydraulic loading system through a hydraulic jack with hand pump, and the pressure decline caused by the rheology of gasket and specimen can be compensated during the high pressure in-situ neutron diffraction experiments. The opposite anvil system attached on a four dimensional pensile-type translational stage is aligned by means of two lasers, and the entire system can be easily assembled and distributed. The pressure calibration results show that the sample pressure is above 12 GPa with WC anvils at a loading force of about 150 kN.

The occurrence of frequency aliasing and its representation in time and frequency domain are analyzed with sampling theory. Relationship between the sampled signal and the original signal is calculated and shows that the frequency of the original signal can be recovered by using the rule of frequency aliasing. Ideal sampled signals with frequency aliasing are simulated, and the frequency recovering method is confirmed by numerical simulations. The interior ballistic velocity in a two-stage light gas gun is measured by a laser displacement interferometer and the optical beam break method. The frequency of the laser interference signal recovered by aliasing rules is the same as the frequency obtained from the optical beam break method, which solves the contradiction between the recording length and the sampling frequency in high velocity measurements of long time duration, such as interior ballistic velocity measurement.

In order to research the mid-far field pressures of the incident shock wave on the fluid-solid interface, an experiment was designed to measure the shock wave pressure, by means of two PVDF piezoelectric film sensors laid on the bottom of double shell. The experimental process was simulated by the finite element method software ANSYS/LS-DYNA. The simulation results are in good agreement with the experimental data. PVDF sensor can be used to measure the incident shock wave pressure on the fluid-solid interface. The mid-far field pressures of the incident shock wave on the fluid-solid interface can be gained, which is important to evaluate the antiknock performance of ships.

The high-velocity normal impacts of space debris on bumper of spacecrafts were studied through a two-stage light gas gun launching 2017-T4 aluminum spheres to impact on 5052 aluminum mesh shield structure. The resist capability of aluminum mesh shield against high-velocity impact was discussed. For the same areal density, the size effect and arrangement effect on the protection performance of the filled layer were analyzed. Impact velocities of Al-spheres were varied between 2.90 and 4.95 km/s in this study. The diameters of projectiles were 3.97 and 6.35 mm respectively. The impact angle was 0°. The results indicated that the primary capability of the 2A12 aluminum plate comminuting projectile is better than that of 5052 aluminum mesh when the areal density is constant, but as the filled medium, the 5052 aluminum mesh layer provides better protection for the rear wall than 2A12 aluminum plate. In a certain wire diameter range, the 5052 aluminum mesh with smaller wire diameter has better protection performance. Al mesh-Al plate filled layer can break up the projectile to a more uniform size than Al plate-Al mesh filled layer.

The characteristics of the plasma generated by hypervelocity impact have been studied by theoretical analysis and numerical simulation. Based on the theory of thermodynamics and statistical physics, a model of thermal ionization is proposed to describe the relationship between the degree of ionization and temperature. Plasma conductivity related to temperature is obtained by considering the velocity distribution law at heat balance. Three-dimensional model of an aluminum plate impacted by a spherical projectile with 6.0 km/s at an angle of 60° is established, and the corresponding simulation is performed. Then the parameters of the physical model are obtained, and the characteristics of plasma generated by hypervelocity impact are analyzed. There is a good agreement between the model predictions and the experiment results, which indicates that the model is effective and reasonable for analyzing the characteristics of plasma.

Layered plates are normally impacted by ogival, blunt and hemispherical projectiles using a gas gun to investigate the influence of the number of layers on the ballistic resistance and target failure model. The residual velocity versus the initial velocity curves for the projectiles are constructed, and ballistic limit velocities are obtained. Based on the experimental data, the monolithic targets show greater ballistic limit velocity than multi-layered targets. For blunt and ogival projectile, the ballistic limit velocity decreases with increasing of the number of layers. However, for hemispherical projectile, the ballistic limit velocity firstly decreases and then increases with the increase of the number of layers. The influence of layering decreases as the impact velocity of projectile increases.

In order to study the relation of powder liner material density and performance of the shaped charge jet, the curves of shaped jet velocity, jet particle momentum and jet particle kinetic energy with respect to the liner density were calculated under the same charge conditions, according to the Birkhoff's steady theory and Gurney's formula of crushed speed. In the same charge structure, the jet velocity and penetration power of two kinds of powder liner were tested, whose mass ratios of W to Cu were 0.5∶0.5 and 0.4∶0.6 respectively. It is found that the experimental results are well in agreement with the calculation results. Therefore, it is considered that the calculated curves have certain reference values, and the penetration power can be increased effectively by improving the density of powder liner.