Discrete element method for predicting the behavior of concrete under dynamic loading

Abstract
High strain rate tests are simulated by a 2D discrete element method. This method is well adapted to problems involving fracturing and fragmentation of heterogeneous materials and geomaterials. The mesh is a Voronoï diagram, the associates Delaunay diagram being the set of the links between each cell and its neighbors. Each link is characterized by local parameters Kⁿ and K^s, the normal and the shear stiffness. Furthermore, rupture thresholds Φⁿ and Φ^s are introduced to simulate mode-I and mode-II crack. A numerical code based on this method is used to simulate the effects of contact explosion on a 20 cm width concrete slab. Synthetic results are compared with experimental data. Compaction, fracture propagation and damage are well-fitted. It is shown that the phenomenology is complex and depends on, strain rate loading and porosity of target materials.