Numerical study on explosion-induced fractures of reinforced concrete structure by beam-particle model

In the field of disaster prevention mitigation and protection engineering, it is important to identify the mechanical behaviors of reinforced concrete (RC) under explosive load by simulation. A three dimensional beam-particle model (BPM), which is suitable to simulate the fracture process of RC under explosive load, has been developed in the frame of discrete element method (DEM). In this model, only the elastic deformations of beams between concrete particles were considered. The matrix displacement method (MDM) was employed to describe the relationship between the deformation and forces of the beam. A fracture criterion expressed by stress was suggested to identify the state of the beam. A BPM for steel bar, which can simulate the deformation of steel bar under high loading rate, was also developed based on the Cowper-Symonds theory. A program has been coded using C++ language. Experiments of RC slab under explosive load were carried out using the program. Good agreement was achieved between the experimental and simulated results. It is indicated that the proposed theoretical model can well simulate the fracture characteristics of RC slab under explosive load such as blasting pit formation, cracks extension, spallation formation, etc.