Shear Band Initiation of Brittle Damage Materials

Some effects of material degradation on failure mechanisms of brittle damage materials are investigated. Conditions for the localization of deformation within a shear band are established for rate independent damage materials. In contrast with previous work on shear band initiation that relied on plasticity and flow theory formulation, the present study finds it sufficient for the shear band to emerge in the regime of infinitesimal strain for brittle damage materials. Bifurcations from the homogeneous deformation mode in the form of shear bands are captured for loading conditions of plane strain compression and uniaxial compression using conventional continuum damage mechanics formulations. The inclination angle and critical strain for shear band initiation are calculated using well-established mathematical theory. A finite element simulation of shear band initiation for a rectangular mesh deformed in plane strain compression is also presented.