Liquid crystal optical elements have important applications in laser facility, and the indium tin oxide (ITO) films are generally used in liquid crystal optical elements as transparent conductive electrodes. Laser induced damage of ITO films leads to failure of liquid crystal optical elements. The laser damage model of ITO films which simulates the temperature distribution and thermal stress distribution was established. The laser damage of ITO films was experimented through pump-probe technology, and the power density producing damage at a probability of 50% (i.e., damage threshold) was obtained by 1-on-1 testing, and the square resistance of the film after laser irradiation was also measured. The experimental data basically agree with the simulated results. The results show that 1 064 nm laser damage of ITO film occurs mainly by thermal stress. The damage of ITO film begins from K9 glass substrate after CW laser irradiation, while the damage begins from the surface of ITO film after pulsed laser irradiation. Furthermore, the laser damage thresholds decrease with the increase of thickness of ITO films. The square resistance of ITO films increases with the increase of laser intensity unless the ITO films have been damaged completely. The optimal thickness of ITO film in liquid crystal optical element depends on the factors of laser damage, transparence and square resistance.

In order to analyze the flow field within the microchannel of dynamic high-pressure microfluidization, the geometric model and mesh model are established, and the pressure and velocity distributions of the flow field in interactive chamber are obtained with SIMPLEC solution algorithm and RNG k-ε model using FLUENT software. The simulated results show that the high-speed jet flow impinging increases the acting force field, and the sharp increment of the flow velocity rapidly increases the velocity gradient and shear stress. All these ensure the excellent effect of the high-pressure microfuidization. In addition, because of the opposite change of the static pressure and velocity in the oscillating chamber, the dramatic changes of static pressure greatly enhance the effect of gas cavity and pressure release, which corrode the material of the interactive chamber. It is desirable to appropriately decrease feeding speed, reduce the fluid separation inlet corner angle, and choose a short discharge nozzle on the condition of ensuring the impinging speed when designing the internal microchannel of interactive chamber.

The loading and unloading paths of shock impact on granular metal were analyzed, and the attenuation of planar explosion shock wave in granular metal was investigated using characteristic method. The results showed that the initial peak pressure of the shock wave was determined by the type and property of the metal, porosity and detonation velocity of the explosive. The higher of impact impedance and porosity of metal and higher the detonation velocity were, the higher initial peak pressure was. The attenuation was determined by the length of explosive, impact impedance and porosity of the metal. The higher of impact impedance and porosity of metal and shorter explosive cylinder was, the more quickly the shock wave attenuated.

A series of plate impact experiments were conducted to probe into the free-surface velocity profiles characteristics of ultra-pure aluminum (Purity: 99.999%) by a velocity interferometer system for any reflector (VISAR). Based on the observed differences of pullback signals in amplitude, pulse width, and two “sudden changes”, the wave profile evolution during fracture process of ultra-pure aluminum from incipient spall to complete rupture is discussed in detail. The reasons for these change behaviors are analyzed with the mesoscopic analysis of “soft-recovery” sample. This paper points out that these characteristics are possibly related to the release rate of stress wave energy and the fracture behavior of material grain. These analysis results are helpful to understand the evolution process of ductile metal dynamic damage.

An elastic/viscoplastic pore collapse model of double-layered hollow sphere, in which the effect of the binder in Plastic Bonded Explosives (PBX) was taken into account, was developed as a hot-spot ignition model in shocked explosives. The space and time distributions of the velocity, strain, temperature and chemical reaction rate in shock compression of the explosive hollow sphere were theoretically calculated. A new expression of reaction rate equation was obtained for the hot-spot ignition. The three-term reaction rate model, consisting of the new hot-spot ignition term, the slow burning term at low-pressure from Kim and the high-pressure reaction term from ZHANG Zhen-Yu, was implemented into the two-dimensional, hydrodynamic finite-element code DYNA2D and used to simulate the one-dimensional shock initiation process of PBX-9501 explosive. The numerical results show that the model can successfully explain the influence of strength and content of the binder in PBX on the shock initiation, and that of particle size and porosity as well.

Nanocrystalline copper was fabricated by severe plastic deformation of coarse-grained copper at high strain rate under explosive loading. The average grain size of the samples was tested by X-ray diffraction analysis, and the deformation process was simulated recur to LS-DYNA3D finite element program. The influence of strain on the grain refining were analyzed quantitatively. The results show that it is feasible to fabricate nanocrystalline copper by explosively dynamic plastic deformation of coarse-grained copper and the grain size of the NC copper can be controlled less than 100 nm, the higher strain is beneficial to the grain refining, and the distribution of the grain size is not uniform along the loading direction.

Parallel computing of 3D explosion and shock processes on the parallel computer is effective means for the large-scale numerical study of explosion and shock process. Considering the complexity of the parallel programming, the overall strategy for parallel programming of 3D mutil-material hydro-elastoplastic hydrocode MMIC-3D was discussed, and the PMMIC-3D parallel hydrocode was designed based on MPI (Message Passing Interface). In addition, a practical plan of program testing was presented. The speedup, efficiency and scalability of the PMMIC-3D parallel hydrocode were tested on the cluster consisting of 8 nodes based on the numerical example of shaped charge jet, and the effect of the bottlenecks of PMMIC-3D parallel hydrocode was discussed.

This paper mainly focuses on the experimental investigation of the gaseous detonation wave build-up mechanism for hydrogen-oxygen mixture in shock tube. Five pressure sensors were used to record the pressures and a high-speed camera was used to capture velocities of flame, shock, or detonation wave. The high-speed camera records the transformation of flame, shock in the ignition phase and the attenuation of detonation wave. The experimental results show that the diagnostic system can effectively measure the DDT. The images of flame propagation show that the flame front is curving and dispersive. It is found that the interaction of shock and turbulent flame is a dominant factor for the onset of explosion. In the smooth tube, experiments indicate that the intensity of shock wave continually increases due to the acceleration of flame. The local explosion occurs in the reaction zone when the intensity of shock wave arrives at a critical pressure p_c when some hot spots form in the local explosion centers. At that time, an unsteady detonation wave is formed immediately, and after a period of the propagation or attenuation process, it eventually evolves into a steady detonation wave.

The electronic structures of pure ZnS, N-doped and Al-N codoped zinc-blende ZnS were calculated by using first-principles ultrasoft pseudo-potential approach of the planar wave based upon the density functional theory, and the band structure, density of states and Mulliken charge population were studied. The calculated results revealed that N-doped ZnS caused formation of deep N acceptor levels in the band gap and the carriers (hole) which were provided by N 2p states were localized near the top of the valence band. But the codoping calculation revealed that the acceptor levels showed broadening and non-localizing, and the concentration of impurities, the stability of the system were enhanced. Our calculations indicate that codoping of Al and N is in more favor of the formation of p-type ZnS.

A theory model to calculate the target resistance is established to evaluate the ballistic properties; the parameters used in the numerical simulations were determined by simulating the experiment of long rod penetration into alumina ceramic target; the theoretical model is proved to be reasonable by simulating the penetration of shaped charge jet into alumina ceramic. The impact of the geometric size of the shaped charge on the jet velocity and penetration results was studied. It can be concluded that the bigger the angle and the thickness of the shaped charge are, the lower the jet velocity is, and the impact of the thickness on the velocity gradient is severe; the angle of the shaped charge has a significant influence on the penetration depth.