Modeling brittle fracture with the nodal-based discontinuous deformation analysis

The finite element method (FEM) has been successfully applied to solve continuum-based engineering problems, and the discontinuous deformation analysis (DDA) has emerged as a more attractive model than the continuum-based methods for rock engineering problems due to its intrinsic feature of block discontinuity at the contact boundaries. This paper presents a hybrid approach for two-dimensional problems which takes the advantage of both the FEM and the DDA in solving problems involving continuum and discontinuum domains. The hybrid FEM/DDA method, named as the nodal-based DDA (NDDA), significantly improves not only the accuracy of stress distribution inside the DDA block but also the computational efficiency. A cracking scheme based on failure time is introduced to the NDDA so that it can handle the crack propagation inside blocks. Two validating examples show that the newly developed NDDA can model the brittle fracture well.