Countermeasures design and analysis for occupant survivability of an armored vehicle subjected to blast load

Abstract

The demand for blastworthy structures increases due to a large number of casualties in the armored vehicle undergoing improvised explosive device (IED) and landmine attacks. In this research, the numerical studies on the countermeasure analysis to reduce injury biomechanics risk were conducted. The available experiment data of occupant survivability test on a medium size tank was used to validate the numerical model. The subsystem evaluation in this study included the finite element modeling of military personnel, seat system, surrounding interior system, seatbelt, and restraint system with four running conditions. The military personnel inside the armored vehicle was modeled by using Hybrid III 50th percentile anthropomorphic test device (ATD) and its biomechanical response was monitored on the head, neck, thorax, spine, femur, and tibia. The load case for this study referred to NATO STANAG 4569 level 3b with 8 kg TNT explosive load underbelly. The injury assessment reference values (IARV) for the regulation used in this study were based on AEP-55 volume 2. Based on this study, the critical injuries identified on the head injury, neck compression, and tibia axial load. The solid frame as part of seat structure appeared to contribute to an excessive kinematic on the lower extremities. The vehicle acceleration resulted from the load blast was directly transmitted to the lower extremities, resulting in unintended kinematic and interaction on the passenger body. The proposed solutions were to introduce a flexible mounting for the seat system and as well increasing the height of the footrest to avoid direct transmission of vehicle acceleration. The modified countermeasure design reduced significantly head, neck, and tibia injury criteria more than 90 % from the baseline design (existing design). The new anti-mine seat design successfully passed all the standard regulation thresholds of injury criteria.