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The kinematic response (including plastic deformation, failure initiation and fracture) of a soft-skinned vehicle (represented by a F800 series single-unit truck) to the detonation of a landmine shallow-buried in (either dry or saturated sand) underneath the vehicle's front right wheel is analyzed computationally. The computational analysis included the interactions of the gaseous detonation products and the sand ejecta with the vehicle and the transient non-linear dynamics response of the vehicle. A frequency analysis of the pressure versus time signals and visual observation clearly show the differences in the blast loads resulting from the landmine detonation in dry and saturated sand as well as the associated kinematic response of the vehicle. It is noted that the dominant vehicle structural response to the blast is similar to the first torsional structural mode shape obtained through an eigenvalue analysis of the system. Tailoring the vehicle modal response may result in more desirable modes of failure.

A comprehensive finite element investigation is carried out of the effect of up-armouring on the off-road performance of a prototypical high-mobility multi-purpose wheeled vehicle. The effect of up-armouring on the vehicle performance was investigated under the following off-road manoeuvres: straight-line flat-land braking; straight-line off-angle downhill braking; sharp left turn. In each case, the appropriate vehicle performance criteria are identified and the parameters used to quantify these criteria are defined and assessed. The computational results obtained clearly revealed the compromises in vehicle off-road performance caused by the up-armouring employed to improve vehicle blast and ballistic protection performance and survivability. The results obtained are also analysed and explained in terms of general field-test observations in order to judge the physical soundness and fidelity of the present computational approach. Finally, the potential benefits and ramifications of lightweight up-armouring in providing the needed level of blast and/or ballistic performance while causing fewer compromises in the vehicle off-road performance are also discussed.

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A comprehensive finite-element-based computational investigation of the ability of different measures (e.g. up-armouring, seat cushion, or seat belt restraint system) to protect the occupant(s) of a prototypical high-mobility multi-purpose wheeled vehicle in the event of an anti-vehicle mine detonation under the vehicle's front right wheel is carried out. While assessing the effectiveness of these protective measures, different injury criteria had to be defined and/or employed, their values calculated (during the initial response stage of the blast event), and compared with the limiting values corresponding to the critical levels of injury. The efficacies are compared both when these measures are implemented in isolation and in the presence of other protective measures with respect to specific injuries.

Since ballistic and blast survivability and off-road handling and stability of military vehicles, such as the high-mobility multi-purpose wheeled vehicle (HMMWV), are two critical vehicle performance aspects, they both (including the delicate balance between them) have to be considered when a new vehicle is being designed or an existing vehicle retrofitted (e.g. up-armoured). Finite-element-based transient non-linear dynamics and multi-body longitudinal dynamics computational analyses were employed, relatively, in the present work to address the following two specific aspects of the performance of an HMMWV: first, the ability of the vehicle to survive detonation of a landmine shallow buried into sand underneath the right wheel of the vehicle and, second, the ability of the vehicle to withstand a simple straight-line brake manoeuvre during off-road travel without compromising its stability and safety of its occupants. Within the first analysis, the kinematic and structural responses (including large-scale rotation and deformation, buckling, plastic yielding, failure initiation, fracture, and fragmentation) of the HMMWV to the detonation of a landmine were analysed computationally using the general-purpose transient non-linear dynamics analysis software ABAQUS/Explicit. The second analysis was carried out using Simpack, a general-purpose multi-body dynamics program, and the main purpose of this analysis was to address the vehicle stability during the off-road travel. The same sand model was used in both types of analysis. Finally, the computational results obtained are compared with general field-test observations and data in order to judge the physical soundness and fidelity of the present approach.

Purpose -A parallel finite-element/multi-body-dynamics investigation is carried out of the effect of up-armoring on the off-road performance of a prototypical high-mobility multipurpose-wheeled vehicle (HMMWV). The paper seeks to investigate the up-armoring effect on the vehicle performance under the following off-road maneuvers: straight-line flatland braking; straight-line off-angle downhill braking; and sharp left turn. Design/methodology/approach -For each of the above-mentioned maneuvers, the appropriate vehicle-performance criteria are identified and the parameters used to quantify these criteria are defined and assessed. The ability of a computationally efficient multi-body dynamics approach when combined with a detailed model for tire/soil interactions to yield results qualitatively and quantitatively consistent with their computational counterparts obtained using computationally quite costly finite element analyses is assessed. Findings -The computational results obtained clearly reveal the compromises in vehicle off-road performance caused by the up-armoring employ to improve vehicle blast and ballistic protection performance/survivability. The results obtained are also analyzed and explained in terms of general field-test observations in order to judge physical soundness and fidelity of the present computational approaches. Originality/value -The paper offers insights into the effects of up-armoring of the HMMWV on off-road vehicle performance.