MODELING FRAGMENTATION OF A 155MM ARTILLERY SHELL IED IN A BURIED MINE BLAST EVENT

The shapes of Improvised Explosive Devices (IED) used by insurgents in recent conflicts are complex and can take many forms. To model unique shapes that are embedded in the soil, in addition to the actual shape of the High Explosive (HE), adds to the complexity of simulating the mine blast event. By considering an artillery shell as the container, further complicates the analysis because fragmentation of the shell has to be included. Unfortunately, this complex IED is not uncommon and in order to develop protective structures for our soldiers and civilians, finite element techniques are employed. The work presented is an investigation of how to do this modeling using the explicit non-linear transient finite element software, the IMPETUS Afea Solver^®. The first step is a large sensitivity study of an explosive driven expansion of a simple cylinder and the outcome influence of nine design variables, leading to hundreds of computational hours. The modeling approach chosen for the HE is the discrete particle method (DPM). Applying the knowledge obtained from the expanding cylinder simulations, a model was created to simulate the explosion of a buried mine in the form of a structurally representative IED. The structure for the IED resembles a M795 artillery shell. To capture the fragmentation, the node splitting algorithm available in the IMEPTUS solver is used. The soil and HE are represented as discrete particles and modeled using the IMPETUS DPM algorithm. The blast ejecta target structure utilized is a modified model of the TARDEC Generic Vehicle Hull containing a seated IMPETUS Afea Hybrid III 50^th Percentile Dummy.