SIMULATION OF THE POLY- AND MONODISPERSED GRANULAR MATERIAL. PART II: THE STABILITY STATE CHARACTERIZATION / DAUGIADISPERSIO IR VIENDISPERSIO DALELIŲ MIŠINIO ELGSENOS TYRIMAS. II DALIS: STABILUMO BŪSENŲ CHARAKTERIZAVIMAS

Abstract

In the Part I of the paper, structure of granular aggregates obtained after compaction of poly- and mono-dispersed spherical particles was characterized in terms of the coordination number, particles contacting forces and volume fraction distributions. This part of investigation deals with characterization of the state of stability under quasistatic conditions of the formed granular aggregate structure. The proposed method is based on visualization of the plane of the particle radius size plotted normally to the particle velocity vector. At the beginning of the compacting process, when the discrete particle drops down under the gravity acceleration (almost free of contact with other particles), the planes plotted the cylinder-like pattern at each time step. At the quasistatic state, when the acceleration of the settled particles tends to negligible values, the plot of these planes represents a certain texture appearing on the particle surface. For the interpretation of these textures, Shilnikov's homoclinic bifurcation theory was discussed and applied. In particular, it was found that textures specifying the quasistatic state mainly resulted from the resonant effect depending on the degree of freedom of the analyzed particles. Santrauka Šioje straipsnio dalyje pagrindinis dėmesys skiriamas viendispersinio ir daugiadispersio sferinių dalelių mišinio mikrobūsenai charakterizuoti, analizuojant atskirų mišinio dalelių stabilumą esant kvazistatiniam būviui. Tiriamos ir vizualizuojamos atskirų dalelių greičio vektorių normalinių plokštumų formuojamos tekstūros, kurios esant kvazistatiniam būviui interpretuojamos kaip tam tikri rezonansinio poveikio dariniai, gaubiantys dalelių paviršių.