Dynamic cylindrical cavity expansion model and its application to penetration problems were studied. Both incompressible and compressible bilinear strain-hardening material models were considered. First, solutions for dynamic cylindrical cavity expansion (DCCE) are obtained in terms of the velocity of plastic wave front, radial stress distribution and stress on the cavity surface. The influence of material properties such as compressibility, elastic-plastic constitutive equations and plastic modulus is discussed. Based on the DCCE models, penetration equations are then constructed. Comparison with experimental penetration data shows reasonable agreement between theory and experiment. It also shows that material properties such as plastic modulus have considerable effects on the dynamics cavity expansion and its resistance to penetration.

Reasons of imaging excursion of two rotating mirror high speed cameras used simultaneously are discussed, and the influence to images are analysed according to the theories and experiments, such as the signal drift of the magnetoelectric sensor and improperly operating etc. Finally some measurement are taken to reduce the image excursion.

The effect of ultra-high pressure processing on the microstructure of Bacillus subtilis AS 1.140 was investigated, and the inactivation mechanism of its vegetative form and spore was studied. The change of B. subtilis microstructures were analyzed and compared in terms of the oberation with a Transmission Electron Microscope (TEM) after UHPP (500 MPa, 60 ℃, 20 min). Results showed that the vegetative cell wall of B. subtilis was shrinked, breached and leaked out cytoplasm, the layer structure of cytoplasm disappeared, and a large electron transmission area appeared in the cell after compression. The outer coat of its spores was also breached, the layer structure of spores' inclusion disordered, the inclusion leaked out from the cell, and a partial electron transmission area appeared after compression.

The compressive stress-strain behaviors of polyurethane foams in four different mass densities have been tested by SHPB at strain rates of 1×10³~5×10³ s^-1. Experimental results show that the compressive behavior of the polyurethane foam is sensitive to the strain rates between quasi-static experiments and SHPB experiments. However, the behavior is not sensitive to the strain-rate under condition of dynamic compression. A experiential constitutive relation, which considers density effect of the foams on materials features at high strain-rates, has been proposed based on Sherwood model. The relation is well agreed to the experimental data.

Smooth particle hydrodynamics (SPH) is a new effective numerical method for modeling problems involving large deformation. However when the SPH method is used to simulate shock waves come across contact interface, tensile instability occurs at the contact interface. In this paper we use contact algorithm which describes contact interaction between SPH particles by means of Riemann solution to simulate the propagation of wave in shock tube and projectile impact problems, and compare the numerical results with the analytical solutions. From the compared results, we can conclude that the modified SPH method do well in removing instabilities and improving accuracy of calculation. And due to the introduce of Riemann solution, there is no need to use artificial viscosity and heat flux, which simplifies the program code.

Experiments were performed to investigate the quasi-isentropic magnetically driven flyer plates with several sizes on FP-1, and their velocity histories were recorded by VISAR. When the maximum current was 3 MA, the maximum velocity of flyer plate was 797.3 m/s. Through this work, we get the principle technique for quasi-isentropic load. This will be helpful to further development of the magnetically driven quasi-isentropic load technique, launching flyer plates technique and the study of equation of state.

Campbell's and other authors' experimental studies of behaviors of initiation and after-initiation for heterogeneous explosives were introduced and analyzed, but initiation conditions were not dealt with. When an intense shock wave enters a heterogeneous explosive charge, detonation is initiated by the shock wave instantaneously (i.e. not to undergo induction time) and directly (i.e., not to pass through other processes, such as deflagration). Then a building up detonation wave propagates throughout the heterogeneous explosive charge until it develops into a normal detonation. This whole process is called the buildup of detonation with the new definition in this paper. The so-called reactive shock wave is the building up detonation wave in early stage. Buildup of detonation (in terms of new definition) is a characteristic for all secondary explosives. Incomplete reaction and running to complete reaction of explosives are the chemical mechanism of buildup of detonation.

Numerical simulation for the initiation or ignition of explosive with aluminum shell was carried out following the Lee-Tarver initiation model of the Autodyn-2D code when it was impacted respectively by sphere or column form fragment. The influence on charge detonation of the shape and velocity of fragments, and the thickness of aluminum was analyzed. By means of the “up-down” method, the critical detonation velocity of Octol was obtained.

The D shaped cavity has been used to measure the radiation temperature in Hollraum on ‘Shenguang Ⅱ’ laser facility. The radiation temperature was measured using two methods. One method measured the shock wave velocity produced in low-Z materials such as Al driven by the emission from hohlraum. The shock velocity was detected using optical streaked camera to observe the optical signal emitted from the rear of a step Al placed over a hole in the cavity wall. The second method measured the re-radiated X-ray flux from the cavity wave viewing through another hole in the cavity with soft X-ray spectrometer. Both methods have been shown to provide a consistent characterization of the X-ray drive in the cavity target. The experimental results were analyzed using a model that was based on heat wave similarity and energy conversation law.

Elastic P wave velocity (v_P) and quality factor value (Q_P, on behalf of attenuation) of dunite are determined using ultrasonic pulse transmission and spectral ratio methods in a multi-anvil apparatus up to 4.0 GPa at room temperature. During the experimental pressure range (0.4~4.0 GPa), v_P and Q_P increase about 11.8% (from 7.6 km/s to 8.5 km/s) and 393.3% (from 54 to 266.4). The experimental results show that v_P and Q_P are pressure dependent and a greater rising rate at the lower pressures than that at higher pressures: the increase rate of Q_p at 0.4~2.4 GPa is 358.5%, while only 7.6% at 2.4~4.0 GPa. At the lower pressures, the pores with low aspect ratio in rocks are easy to close, and almost all of them would close with the pressure increasing. As a result, the samples show the internal inherent elasticity of the whole constituent minerals themselves and the increasing rate of v_P turns lower at the higher pressures. As the pressure rising (0.4~2.4 GPa), Q_P of dunite increases because the energy loss in the pores and between the surfaces of cracks and the mineral boundaries is reduced due to the porosity decreasing and the mineral boundaries contact more tightly. While at higher pressures (2.4~4.0 GPa), most microcracks in dunite have been closed and mineral grains are compacted very tightly, as a result the internal frictional energy loss due to the relative motion at the grain boundaries and across crack surfaces became less, which results in small change of elastic wave attenuation in dunite.