PSI - Issue 14

D R Makwana et al. / Procedia Structural Integrity 14 (2019) 44–52 D R Makwana, Dr D G Thakur, K Senthilkumar/ Structural Integrity Procedia 00 (2018) 000–000

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depends on the moments of inertia around the centre of gravity. The jump height depends on the mass of vehicle, location of blast, type of explosive, ground conditions and stand-off between the hull and the blast. 5.3. Drop down effects After reaching its maximum jump height the vehicle will fall due to gravity. The jump and free fall will depend on the position of the vehicle. In actual scenario, the vehicle may be in dynamic condition and hence the effects of lift may differ from the experimental set-up case. The moving vehicle will not drop down on the original place. Therefore, in case of static loading conditions, it is possible that the vehicle drops down into its own crater, causing higher vertical loadings than in an actual incident. Free fall also causes higher acceleration on the occupants which results in the casualties. 5.4. Subsequent effects Subsequently effects like roll over and frontal crashes after the mine detonation may also take place. Based on the type of mine, like shaped charge or with sharp nails, the effects on the occupants would be different causing a very high accelerations. This may also result in fragments, toxic fumes and gases, blast overpressure and heat, which are serious threats for the human body as well. 6. FE Model Development The model used in the present analysis is improved version of Mine Protected Vehicle. For simplification of the analysis, only V-hull is considered. The hull geometry is designed in such a way to reduce the effects of the blast. As shown in Fig. 5, the shape of the hull bottom is considered as V-shaped.

Fig. 5. Layout of Deformable Hull of Vehicle

The turret, hatches, and interior bulkheads have been removed as they have a negligible effect on the response of the hull in the first few microseconds of the event, which is the duration of the interest here. The wheels and the drive shafts have also been removed to simplify the model. These components play a much more vital role in the response of the vehicle and in the local deformation of the hull, e.g. the wheels can absorb and deflect a significant amount of the blast, but the loading model used in the analysis is incapable of explicitly model their effect on the blast. The engine and transmission block along with their attachment points are also hidden. For the purpose of assessing the blast effect, only the bottom V-hull portion with a simplified axles and gear box have been considered for further loading and analysis.