Skripnyak E.G.   Skripnyak N.V.   Skripnyak V.A.   Skripnyak V.V.   Vaganova I.K.  

Multilevel simulation of mechanical behaviour of heterogeneous brittle ceramics under dynamic loading

Reporter: Skripnyak V.A.

In the present work, approach of computational mechanics of materials has been used to investigate the mechanisms of deformation and damage accumulation in brittle ceramics under dynamic loading. Multilevel computer simulation method was used for simulation of the mechanical behaviour of structured nanoceramics and ceramic composites. The computational models of the structured representative volume (SRVE) of ceramic composites were developed using the data of microscopic researches on meso-, micro -, and nanoscale levels.  Results of numerical simulation of stress pulse loadings on model ceramic materials SRVE are presented. It was shown that isolated micro- and meso-scale cracks can be nucleate in ceramic composites under stress pulse amplitude less than the Hugoniot elastic limit. The critical fracture stress on meso-scale level depends not only on relative volumes of voids and particles concentration, but also sizes of corresponding structure elements. Nucleation of local damage, activation of localized-deformation bands and self-organization process of micro-damages dispersed in SRVE are observed in the ceramic structure at high strain rates.
Results of simulation have shown the Hugoniot elastic limit and ceramics damage kinetics under dynamic loading depends on a volume concentration of nano-particles and nano-voids clusters.