Planar shock compression effects on damage and cracking in Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 bulk amorphous alloy are studied using a two-stage light gas gun. The experimental result indicates that the cracking angel θ of bulk amorphous alloy under planar shock compression is smaller than that of traditional compression experiment, it is decided by the highest strain velocity under shock compression conditions in bulk amorphous alloy; part of bulk amorphous alloy surface also is melt by the effects of highest strain velocity and the energy of partial adiabatic shear bands; the crystallization happens in bulk amorphous alloy by the effects of temperature and pressure.

By analyzing both of dynamic behavior and existing constitutive models of concrete, a new constitutive model has been built to simulate dynamic response of concrete. The main factors such as pressure, the third invariant of stress tensor, strain hardening and softening, stain rate and tensile damage have been taken into account in the constitutive model. After calibrating all parameters of the model, simulation of a perforation problem on concrete target has been carried out with the Lagrangian finite element code LTZ-2D. The computed results of residual velocity are well consistent with the test data, and a reasonable figure of fractured concrete target is obtained. Results demonstrated that the built constitutive model could well describe the main characters of concrete under impact loading.

Based on the experimental results of the elastic precursor attenuation along with propagation distance, with rate-dependent constitutive relation including dislocation parameters, and according to the thermally activated dislocation motion model proposed by Gilman, the lower bounds of the initial mobile dislocation densities N₀ and the drag stresses τ₀ have been obtained for LY12-aluminum, MB₂-magnesium and lead respectively on the order of 10⁶ cm^-2 and 0.1 GPa, but for stainless steel, N₀ and τ₀ are on the order of 10⁸ cm^-2 and 1.5 GPa. With the elastic precusor decay curve, the upper limits of the effective viscosity coefficient μ have been given also for LY12-aluminum and magnesium on the order of 10³ Pa·s, and for 2^#-iron and stainless steel on the order of 10⁴ Pa·s.

The second-order manifold method (MM) is used to simulate the dynamic Hopkinson spalling process of rock under shock loading through introducing a criterion of crack initiation and crack growth. The attenuation of stress waves and the spalling process caused by a reflected tensile stress wave are reproduced. The simulation results are compared with theoretical analysis. The thickness of the formed scab and its velocity obtained from the simulation are in good agreement with the theoretical values. MM has proven to be an effective method in simulating the dynamic failure process of materials under shock loading and exhibits some advantages to conventional numerical methods in the study of dynamic failure and related issues.

The incident shock wave focusing and reflection on the two parabolic reflectors were studied by means of high speed photograph technique and numerical simulation method. The experimental shadow photographs and computational density contours were obtained, and the good agreements between the experimental and computational results were presented. The properties of the gasdynamic focus, formed by shock wave focusing, were analyzed. The results show that for both reflectors studied the gasdynamic focus is formed by the collision of two triple points at the axis, and that this focus is located in the vicinity of the corresponding geometrical focus. The shock-shock structures after shock wave focusing are different for the two reflectors. For the shallow reflector, the bow shock waves form on the surface of reflector before the reflection of incident shock wave; it takes long time to complete the focusing once incident shock wave reflects from reflector; the bow shock waves do not intersect each other during the shock wave focusing and reflection. For the deep reflector, it takes short time to complete the focusing, the bow shock waves have intersected during the shock wave focusing and reflector, and this process leads to the more complex shock-shock structure.

The rules regarding the propagation of irreversible phase boundaries along a finite rod are investigated with a phase transition constitutive model based on the simple mixture theory. The results show that the boundary and loading/unloading conditions strongly affect the propagation pattern of the phase boundaries, and the final distribution shapes of the volume fraction for the product phase along the rod are different under various end boundaries. The new phenomena observed in the recent Taylor bar tests are explained in this paper, and the possibility for producing symmetric distributed functionally graded materials with impact method is proposed.

Experimental results showed that the Me₃C (Me means Fe, Ni) pattern carbides produced by the action of catalyst and graphite are main carbon source to form diamond structure under high temperature and high pressure (HPHT). In this paper, based on the empirical electron theory of solids and molecules (EET), the valence electron structure (VES) and interface structure factors of diamond and various carbides are calculated, and the boundary condition of Thomas-Fermi-Dirac-Cheng (TFDC) is applied to the carbide/diamond interfaces. It is found that the electron density of crystal face in Me₃C formed by C—C bonds is continuous with that of diamond at the first order of approximation, but the continuous intensity of different carbide is different. The VES of plane composed of C atoms in (FeNi)₃C and Co₃C are more similar to that of diamond, so the energy needed to transform their C—C bonds to diamond structure is lower. The catalyst action and catalysis mechanism are explained on the basis of VES concerning the carbides and diamond. This method may be a new way to investigate the mechanism concerning diamond formation.

A combined discrete element method (DEM) and finite element method (FEM) is presented. A 2D program is developing for application to mesoscale simulation of heterogeneous and homogeneous material under shock loading, and the numerical simulations are testified. The results of simulation are in agreement with those of theory, which verifies that the combined method is viable.

The equation of compression isentropes derived from linear and quadratic Hugoniot curves has been obtained by employing the Hugoniot as the reference of Grüneisen EOS as well as from p=f(e, v) form EOS directly. The compression isentropes of aluminum and copper are calculated with both Grüneisen and Appy EOS. The calculated results show that the compression isentrope of aluminum under 200 GPa calculated with Appy EOS approaches to that with the linear Hugoniot, where the error is less than 1.5%. It is also compared with the ICE data of Shot Z864 at the Sandia Z machine. They agree very well under 200 GPa and derived from both the linear Hugoniot and the Appy EOS, for those where the error is less than 1%. The isentropes of aluminum derived directly from Appy EOS coincides almost with the experimental one.

MgSiO₃ perovskite and ferropericlase (Mg, Fe)O are generally considered as the most dominant components in the Earth's lower mantle. The experimental data of these phases at high pressures and high temperatures play a key role to constrain the composition of the Earth's lower mantle. However, high pressure experiments at lower mantle conditions, especially the shock wave experiments, are restricted since it is impossible to collect the high-phases of the samples in nature. We introduce the experimental methods to synthesize large bulk MgSiO₃ perovskite and ferropericlase (Mg, Fe)O using piston-cylinder and mutli-anvil apparatuses, and the synthesized samples were analyzed by micro electronic probe, Raman spectrum, and X-Ray diffraction. This makes it possible to do shock wave experiments with the large bulk MgSiO₃ perovskite and ferropericlase (Mg, Fe)O as starting materials.