Simulation of fracture/breakup of concrete magazine using cohesive element

Abstract

To determine the potential hazard zone around an ammunition storage magazine is the research interest of many researchers working on explosive safety. Carrying out an explosion test of an ammunition storage magazine is expensive. As such, numerical modeling offers an economical solution to supplement the field tests, and it has been widely used to simulate the magazine breakup. In the literature and own previous studies, numerical simulations often resorted to the Lagrangian finite‐element method and used the nodal‐split algorithm to model the concrete fracture/breakup upon internal detonation. Pitfalls in that approach have not been fully recognized [–]. In it, all elements initially connected to the same node would be spilt in all directions once the nodal strain reached the threshold. This strain‐based splitting criterion lacks of sound physical meaning. To overcome those pitfalls, the present study adopts a kind of interface element, namely a cohesive element, to simulate the fracture/breakup. Strain rate dependent experiments were carried out to obtain the fracture criteria, which were then applied to define the threshold for element‐face split. Results show that it yields good agreement with experiment tests, including Split Hopkinson Pressure Bar (SHPB) on concrete specimen and breakup of concrete magazine upon detonation.