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

High strain rate tests are simulated by a 2D discrete element mehtod. This method is well adapted to problems involving fracturing and fragmentation o f heterogeneous materials and geomaterials. The mesh is a Voronoi diagram, the associates Delaunay diagram being the set of the links between each cel l and its neighbors. Each link is characterized by local parameters K-n and K-s, the normal and the shear stiffness. Furthermore, rupture thresholds p hi(n) and phi(s) are introduced to simulate mode-I and mode-II crack. A num erical 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 w ith experimental data. Compaction, fracture propagation and damage are well -fitted. It is shown that the phenomenology is complex and depends on strai n rate loading and porosity of target materials.