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An explicit failure model for ceramics undergoing a solid–solid phase transition under shock compression is developed and tested on silicon carbide and aluminum nitride. This model enhances the applicability of our failure model recently developed for boron carbide. Smoothed particle hydrodynamics simulations of ceramics under shock loading are performed to optimize the model parameters using the velocity profiles obtained in available shock-wave experiments. It is demonstrated that the inclusion of a phase transition with hysteresis is essential for agreement between simulations and experiments. Evolution of damage spreading in samples with propagation of the failure wave front is discussed. We show that it changes from a homogeneous damage pattern to regular structures of failure bands, where growth is guided by distributions of equivalent stress and shear strength of material within the band tips. [ABSTRACT FROM AUTHOR]

Richtmyer–Meshkov instability developed at a solid–vacuum interface after reflection of a shock wave is studied using the smoothed particle hydrodynamics (SPH) method. SPH simulations are performed for aluminum, copper, and tantalum samples with free surfaces having machined grooves of sinusoidal shape. The obtained simulation results agree well with the experimental data for different loading regimes. Our simulations demonstrate three regimes of material response to shock loading, where conditions depend on the yield strength for a given strain rate. First, at weak elastic shocks, the grooved surface experiences shear oscillations only. Then, a more intense shock loading produces plastic strain resulting in a plastic spike with the limited run from the surface. It is found that after the arrest of the plastic motion, the formed spike oscillates with the same period as in the elastic regime. Finally, the heavy load produces the unlimited growth of plastic or liquid jet, which leads to its fragmentation at later times. The transition from limited to unlimited jet growth depends on the geometry of the corrugated surface. We estimate the critical amplitude of corrugations required for unlimited spike growth. The used simulation techniques can provide the more accurate mechanical properties of materials to achieve a better agreement. [ABSTRACT FROM AUTHOR]

Ceramic materials have a long-term industrial demand due to their high mechanical hardness and chemical and temperature resistance. They are brittle and tend to lose strength under heavy loads which complicates the development of a comprehensive material model for simulation of engineering prototypes containing ceramic parts. We developed an improved failure model of ceramics based on the well-known Johnson–Holmquist approach. This model redefines the damage rate equation using a consistent definition of the total plastic strain in the failed material. It reduces the number of free model parameters and enables the plastic strain to be explicitly accumulated during the failure process. The corresponding non-iterative algorithm utilizing this explicit failure model is developed. It is successfully validated by simulation of the wave profiles obtained in plate-impact experiments with boron carbide using the contact smoothed particle hydrodynamic method. [ABSTRACT FROM AUTHOR]