Fracture of brittle material with initial porosity under high energy density flows.

Some aspects of influence of high energy density flows (like an intensive laser and ion beams) on condensed targets are investigated. The discussion concern mainly with the various types of fragmentation of initially porous brittle materials and their partial evaporation. The complete system of equations for the considered material consists of the energy and momentum conservation laws and the nontraditional conservation law compatibility of displacement gradient and mass velocity. The system is closed by the kinetic equation of the plastic flow, the equation of damage parameter evolution and the wide-range equation of state that allow to simulate describing finite strains and phase transformations from solid into fluid and gas respectively. The use of the equations presented in divergent form gives the opportunity to exploit conservative quasi-monotonic method of Godunov's type of second order of approximation. Nonstructural meshes with changed during calculation topology is used for description of strong deformations of the computational region. This technique was applied to solution of problems on action of laser and ion beams on brittle materials. Typical profiles of different types material fracture are demonstrated. Influence of parameters of matter and irradiation was investigated.