Strong embedded discontinuities for simulating fracture in quasi-brittle materials

Abstract

In this paper embedded strong discontinuities are used to model discrete cracking in materials like concrete. In the approach followed a discontinuous displacement field is considered and the deformation is localized at a surface of zero width. Both a damage law and a plasticity law are adopted to describe the constitutive relation between tractions and displacement jumps at the discontinuity surface. An algorithm is introduced to enforce the continuity of the crack path, permitting a clear identification of the discontinuities in the mesh. Both mode-I and mixed-mode cracking have been considered and the importance of the shear tractions on the global behaviour of a structure is assessed. With the formulation adopted it is concluded that: i) realistic crack patterns are obtained, similar to those found in experiments and ii) the dissipation of energy can be objectively found irrespective of the mesh that is used.