COMPUTER-AIDED SIMULATION OF MATERIAL LOCAL FRACTURE EFFECTS AT THE AREA OF TRIBOLOGICAL CONTACTS ON THE BASE OF METHODS OF DISCRETE APPROACH

摘要

For deep understanding of elementary acts of friction and wear of mechanical systems it is necessary to have an ability to precisely describe material behaviour under external tangential and normal forces. Methods of computer-aided simulation can be useful for this aim. Due to choosing of methods of numerical approach it is necessary to take into account that friction and wear are accompanied by intensive processes of discontinuity formation, damage generation and accumulation. Moreover contact formation its development and fracture are taking place at nano and micro levels. In the paper modelling of contact area at atomic- and meso-scale levels was carried out on the base of discrete computational approach (method of particles). Molecular dynamic method was used at micro level, movable cellular automata method - at nano-scale level. Movable cellular automata (MCA) method provides the necessary information about response of different homo- and heterogeneous materials, composites and layers under uniaxial compression, indentation and sliding conditions. Due to mobility of the separate automata the MCA method allows to simulate different processes ongoing in the real materials during impact, beam bending, friction and wear, e.g. formation and accumulation of damages, grinding and penetration effects, fracture processes, fragmentation, formation of pores and cracks. Because of the possibility of the MCA method to choose the scale of simulation, the results of MCA simulation can help to understand elementary processes under impaction of normal and tangential forces.