SPH Simulation Of Thermo-Mechanical Effects In Materials Under Pulse X-rays Radiation

This paper aims to simulate the thermal-mechanical effects in metal plate under x-ray radiation with Smoothed Particle Hydrodynamics (SPH) method. The main work consists of five parts. The first, the summary on interaction of X-rays with matter, energy deposition and thermo-mechanical effects is obtained through investigating references. The second, the dependence of the sublimation energy on pressure and temperature is studied by thermodynamics theories. In the third part, the kernel of SPH method is known by learning its basic theory, and a SPH program is designed for simulating the one-dimensional free explosion process of high pressure gas. In this program a new method is raised to deal with the free boundary conditions. The fourth part is left for computing the energy deposition in materials under pulse X-rays radiation. In the last part, SPH numerical simulation of one-dimensional thermo-mechanical effects in aluminum plate under pulse X-ray radiation has been accomplished, and the gasifying blow-off impulse momentum is calculated. In this part, the change of sublimation energy is considered, and the influence on intensity of thermal shock wave and blow-off impulse momentum is analyzed.After the above research, this paper exerts to achieve the following results:a) A combination of ghost particle method and Riemann solution can achieve correct boundary values with free boundary condition;b) It is revealed that the sublimation energy of metallic materials will reduced linearlywhile the temperature and pressure increasing;c) Energy deposition primarily occurs on the side under radiation, and it presents decaying exponential. The depth of energy deposition reduced by hard x-rays is deeper than by soft X-rays, but the cross section of energy deposition under hard X-rays radiation is smoother;d) The intensity of thermal shock wave in materials is related to X-rays model, energy density and sublimation energy of materials, etc. The bigger the energy density of X-rays is, the higher the density of thermal shock wave is; the smaller the materials' sublimation energy is, the higher the density of shock wave is;e) The gasifying blow-off impulse momentum has an intimate relationship with many factors, such as the model and energy density of X-rays, sublimation energy of materials. For the same kind of material, the blow-off impulse caused by X-rays radiation will enlarge with the energy density increasing. When the sublimation energy decreases, the impulse will increase contrarily.