Numerical modelling of VBIED blast and vehicle fragmentation

A terrorist weapon of choice is often a Vehicle-Borne Improvised Explosive Device (VBIED). Explosive field trials for VBIEDs have been conducted to characterise and quantify the spatial distribution of blast and vehicle fragmentation hazards. This paper develops an innovative numerical modelling approach to predict VBIED blast loads and vehicle fragmentation trajectories. A 3dto3d mapping technology is used to improve the calculation efficiency needed to calculate the far-field blast loads around a blast-damaged vehicle. The generation and statistical algorithms of vehicle fragmentation are proposed to characterise the initial launch conditions, including fragment mass, launch velocity, launch angle, fragment size and projected area for approximately 12,000 fragments generated from a single VBIED. The spatial distribution of vehicle fragmentation trajectories and landing points are compared with data from a VBIED field trial that helped validate the accuracy of the proposed VBIED numerical model. Significant variability of fragment hazards was observed for small changes in the energetic properties of the explosive charge due to varying climatic conditions.