The small spinning solid rocket motor was employed to perform as the power of the radial twice throwing system. Interior ballistic model of spinning solid rocket motor, in which eroding burn effect was considered, was established. The calculated pressure-time curve was set as initial pressure value for subsequent simulations. Fluid field of nozzle with straight segment was simulatated by software of Fluent, whether fluid field was supersonic or not can be identified. Finally static and dynamic tests of spinning solid rocket motor were performed. The tested results of spinning solid rocket motor indicate that spinning solid rocket motor works well at 19 000 r/min and meets the working need.

For comparison with several methods used to define the location of the onset of detonation, several of experiments were performed to study on the deflagration to detonation transition (DDT) for premixed C₂H₂+2.5O₂ mixture in a shock tube. A high-speed digital camera was used to track the velocities of flame, shock, or detonation wave. In this work, six methods were used to define the location of the onset of detonation, and six different results of the DDT run-up distance (L_DDT) and the time of the detonation onset (t_DDT) were obtained. It is found that the methods based on the flame emission radiation and the growth trajectory of flame, shock, or detonation wave can accurately define t_DDT and L_DDT. The onset of detonation defined by the other methods based on the speed of detonation wave might result in some error or underestimated values due to the localized explosion taking place just prior to the generation of detonation.

The hypervelocity impact interaction of the sphere projectile with continuous shield and mesh shield, which were of the same thickness or area density, was investigated numerically. The study was aimed at mastering the hypervelocity impact characteristics of the mesh shield and applying effectively it in development of lightweight shields. The study involved the differences in the morphology and the distribution of momentum, velocity and mass of the debris clouds generated by impacting two kinds of shields. The calculations show that the morphologies of the debris cloud vary with the impact locations when a projectile impact the mesh shield, and there is the linear distribution of debris in the front of debris cloud. Comparison between the continuous shield and the mesh shield with the same thickness, the maximum of momentum density in the mesh shield is higher than that in the continuous shield, while the maximums of momentum density are almost near in the two kinds of shields with the same area density. The mesh shield does not effectively slow the penetration velocity of projectile, but can break it up. The dynamical response of the projectile varies with the shields. Impacting the mesh shield, the main part of debris is at the rear end of the debris cloud, which is different from the case of continuous shield.

The flash X-ray radiography is an important diagnostic tool for the ejecta from shocked metal surface. The influence of metal surface characteristics on the ejecta is a main aspect of numerical simulations and experiments on ejecta phenomena from shocked metal surface. A commercial flash X-ray tube, a X-ray camera and high accuracy synchronization timing system were used to establish a system of ejecta diagnosis. The radiographs of ejecta from the tin targets with different depths of grooves were captured and analyzed. The experimental results showed that (1) the mass ejection of tin targets with grooves presented the quasi-multilayer in vacuum; (2) the zone width and ejecta mass increased with the depth of target grooves in vacuum; (3) the region width and ejecta mass decreased as in gas pressure of 0.1 MPa.

In order to investigate on cracks propagation of the coal under column charge blasting subjected to geostatic stress, the damage constitutive model was established by considering tension and compression. The improved damage constitutive model was embedded in the FEM software to study the mechanics of cracks propagation coupled by blasting loads and geostatic stress. The precision of simulation is proved because the numerical results are in good with model experiments. The results show that the interaction of the compression wave and unloading wave yield cracks in the coal. The cracks are somewhat inhibited by geostatic stress. The direction of cracks is in accordance with the major principal stress.

The compression experiment of molybdenum foil combined with finite element modeling calculation reveals the history of elastic deformation of diamond and elastic-plastic deformation of sample in the pressure gradient method used for measurement of yield strength at high pressures. The influence from elastic compression and cupping of diamond on the in situ thickness measurement and pressure profiles of molybdenum foil is analyzed. The results show that the elastic compression of diamond is very small and reasonable to ignore at least below 31 GPa which is the highest experimental pressure. The cupping of diamond is somewhat notable. But the agreement of pressure profiles and their pressure gradients between calculation and experiment indicate no evident change due to the influence of cupping of diamond below 31 GPa. The cupping finally leads to the contact of corners of culets at 60 GPa. The proposals of experimental design are also given to reduce the influence from cupping deformation of diamond at high pressure.

Based on the traditional spilt Hopkinson pressure bar (SHPB) apparatus, a SHPB system for testing dynamic compressive properties of materials exposed to high temperature was established after adding a tubular electric furnace, and the dynamic compressive stress-strain curves of concrete at 200~800 ℃ were measured using the system. The results show that the SHPB experimental system can be used to test the dynamic properties of concrete exposed to high temperature; Dynamic compressive strength and critical strain of concrete at different temperatures increase with the rise of projectile velocity; Effects of high temperature on dynamic properties of concrete are remarkable: the critical strain increases with the temperature increasing, dynamic compressive strength increases firstly and then decreases slightly, and decreases rapidly after 600 ℃.

Numerical simulation with ANSYS/LS-DYNA software was accomplished on metal jet being disturbed by shearing movement of four-layer equivalent spaced plates. Disturbing performance of moving plates was analyzed according to jet rupturing forms, energy losing values, and the penetrating depth in target plate. The effects of the plates' velocity and the impact angle on the disturbing performance were obtained. The obtained results are as follow: The increasing of the plates velocity can improve the disturbing ability on jet; the disturbing efficiency was greater with the plates velocity beneath 100 m/s than over 100 m/s; and the disturbing extent can increase with the increase of the impact angle. All those results are significant for mechanical armoring research.

Effects of dynamic high pressure micro-fluidization (DHPM) in the extraction processing on the antioxidative activities of flavonoid from sweet potato leaves by DHPM in contrast to the traditional ethanol extraction were performed to explore the possible mechnism in combination with the high performance liquid chromatography combined with mass spectrum (HPLC-MS). The results showed that pretreatment by DHPM could promote cell rupture and unfolding of cell membrane, which caused the increase in the extraction rate of total flavonoid. The best result was achieved at 100 MPa with the highest yield of 5.440%±0.006%, which was higher by 21.7%, relative to the enthanol extraction. HLPC-MS analysis revealed that pretreatment by DHPM could improve the purity and content of lower polar molecule in extract solvent.80 MPa and 100 MPa pressurization treatment decreased the antioxidant activity of samples with identical flavonoid content, but had negligible effects on elements and structure of flavonoid. Pretreatment with 120 MPa (SF120 sample) pressurization had the strongest antioxidation with IC₅₀ for DPPH and ·OH were (15.99±1.19)mg/L and (0.093±0.012)g/L, respectively. The main flavoniods of SF0, SF80 and SF100 are quercetin, 4′, 7- dimethoxykaempferol, myricetin, ombuin and rhamnocitrin, while, the main flavoniods of SF120 are quercetin, myricetin and ombuin.

The hollow microsphere/aluminum alloy composites was fabricated by press infiltration. The dynamic compression behavior of the composites was investigated by using split Hopkinson pressure bar (SHPB). The microstructure of the specimen after compression was characterized by scanning electron microscopy, and the damage patterns of the hollow microsphere was primarily studied. A single-cell model of the composites was established, and the dynamic compression process of the single-cell was simulated by using the LS-DYNA explicit finite element software. With dynamic loading, mechanical behavior of hollow microsphere/aluminum alloy composites showed three typical stages: elastic deformation, plastic collapse and densification. With the increasing of the decrement, the hollow microsphere appeared cracks along the meridians, gradually transitioned into the fragmentation of the equator, and eventually collapsed.