Micromechanics of wing crack propagation for different flaw properties

•Rock fracturing from an existing flaw is simulated using Discrete Element Method.•The model describes consistently both open and closed flaws.•Various damage mechanisms are highlighted using relevant local stress measurements.•Damage depends on the flaw properties, not only those of the matrix.

The Discrete Element Method is used to study crack propagation in intact rock from pre-existing flaws of different natures. Damage mechanisms occurring during open and closed cracks propagation are analyzed at the local scale using an innovative micromechanical investigation. Different micromechanisms are captured, due to the development of either tensile or deviatoric states of stress in the vicinity of the flaw, which are shown to be dependent on the flaw properties. In turn, crack propagation patterns, as strength, are greatly affected by the mechanical and geometrical characteristics of the initial flaw.