Comparison of macro-scale and meso-scale elasto-plastic damage failure in rocks

Key words:  strain-space  elasto-plastic damage  meso-scale  macro-scale  rock's failure

Abstract:

In order to consider local plastic deformation with a mesoscopic view in rucks,, an eLasto-plastic damage constitutive model based on incremental theory was deduced in strain space f and the failure elements deleting method was used to simulate crack propagaticm in program so as to explicitly show how cracks extend in rocks. The elasto-plastic damage and failure problem of mode I crack was studied at macro-scale level and meso-scale level respectively. The comparison indicates that the mode 1 crack extending accords with the theory of fracture mechanics at macro-scale level. The study on failure process of rocks at meso-scale level can explain meso-failure mechanism. And rock's macro failure was directly connected with meso damage and failure. The iock's failure process of 3-D numerical simulation was more complicated thsn that of 2-D simulation. The simulated r^&uiit of marble's elastopla.stic damage failure agrees well with the experimental result of three point bending beam of mari>le, which proves that the meso-scale level model was suitable to siinuilate problems of rock's failure.