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

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 Ks, the normal and the shear stiffness. Furthermore, rupture thresholds Φn and Φs 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