ИСТИНА

The talk describes the results of developing numerical models for simulation of hypervelocity collisions of small fragments with honeycomb shields relevant to Space structures protection from impact of debris fragments. Numerical modelling of hypervelocity collision within hydrodynamic approach reveals effects that are inconsistent with physical sense. In order to overcome these inconsistencies and to achieve justified description of the process of penetration and fracturing numerical model was developed assuming the impactor and projectile being viscous materials. Despite constant viscosity we investigate two phenomenological relationships for viscosity: depending on temperature and depending deformation rate. The exponential dependence of viscosity on material state (temperature and second invariant of strain rate deviator) makes the material manifest both properties of fluid and solid state of matter. Taking into account viscosity allows to suppress jets at symmetry axis and small-scaled ejecta. The usage of non-constant viscosity results in a more physically based scenarios for fracturing of the shell obtained in numerical simulations.