Numerical study of lignite samples fracture under complex loading conditions

Using the computer simulation the real loading conditions around the coal-bed deep under the surface was reproduced. The calculations were done on the basis of the method of Movable Cellular Automata (MCA). According to the results of simulations the mechanism of fracture of lignite lithotypes can changes from typically brittle to degradation-like or quasi-plastic depending on boundary conditions. Also the influence of loading conditions on fracture process was shown. Obtained results are in good agreement with experimental data. It shows that MCA method can be successfully applied for investigation of behavior and fracture of various heterogeneous media under standard test conditions as well as under very complex loading that is very difficult or impossible to reproduce using experimental procedures.