Numerical parameter characterisation of a buried mine blast event with further emphasis on IED shapes and soil bed conditions

The modelling of a buried charge and its impact on vehicle structures is a complex simulation task since numerous structural variables, physical properties and numerical parameters have to be determined to provide accurate estimation of the structure's response. A number of variables in question are directly related to the numerical approach chosen to perform the analysis while others relate to the overall modelling process and the detail used to describe the physical processes. This paper documents the results of a comprehensive sensitivity study of the structural response of a vehicle subjected to the impulse from a buried charge using the discrete particle method (DPM) to model the soil and high explosive (HE) coupled to a finite element solver for the structure. Fourteen design variables and numerical parameters were studied requiring in excess of 1000 computational hours. The response parameter was chosen to be the total blast impulse (TBI) on the structure. The non-linear transient dynamic explicit finite element solver used for the analysis was the IMPETUS Afea Solver® which has implemented the DPM for blast simulations and is called iDPM. The study includes soil characteristics and charge related parameters. The depth of burial (DOB) and number of discrete particles were also considered in the study. As a natural extension of the sensitivity study the effect of an improvised explosive device (IED) made from an oil can is investigated as well as the effect of having rocks in the soil bed making it a non-homogeneous soil bed.