EVOLUTION OF OCCUPANT SURVIVABILITY SIMULATION FRAMEWORK USING FEM-SPH COUPLING

To reduce the hazard for service personnel involved in current field operations, it is necessary to improve the safety and structural integrity of transport vehicles subjected to buried explosive material. Numerical simulation of the detonation effects of an Improvised Explosive Device (IED) on a vehicle and its occupants can provide tremendous value in this effort. Such events involve a range of complex phenomena at various dimensional and temporal scales, and it is not practical to capture all physical phenomena with just one single numerical method. A practical solution to this problem is proposed using a combination of Smoothed Particle Hydrodynamics (SPH) and Finite Elements.

Various numerical techniques have been proposed for simulating buried explosive over the past 30 years and this work has been previously described by many authors. However, the ability to define blast input parameters together with a soldier-centric simulation approach that includes human body and human-structural interactions with a vehicle subjected to an energetic effect poses a new challenge. SPH technology is a mesh-free Lagrangian method that can be configured with direct input of variables such as the soil density and explosive size without extensive tuning of parameters. The coupled SPH-FE approach is demonstrated for explosions and blast waves interacting with structures using a previously published validation study. For comparative purposes, the inclusion of Anthropomorphic Test Dummies (ATD’s) to a vehicle model subjected to this blast load is presented under varying scenarios.

The PAM-SHOCK software allows combining SPH for the soil, detonation and blast wave propagation in a gaseous medium with Finite Elements for the structural dynamics of the vehicle and the occupant models and is presented in the current study. The proposed approach allows realistic and predictive simulations, based on realistic input, of vehicles and occupants subjected to IED blasts supportive of product development cycle constraints.