A Simple Ejection Mitigation Device to Increase Survival of Standing Gunner

It is a challenging task to provide warfighters protection due to impact related injuries such as skull fracture, lower leg and ankle fractures and neck and spinal injuries, which might occur during underbody blast. Tremendous improvements in design of ground vehicles have minimized these injuries. Further improvement can be achieved by new technology solutions by adding a simple passive device to existing design with minimal changes in order to mitigate occupant ejection for a vehicle occupant experiencing underbody blast while standing at nametag, defilade through round hatch opening as part of their operational duty. The patented device is an energy absorbing box with corrugated sheets in all four sides and welded to the top and bottom plates. The top and bottom plates are connected with brackets. The top plate and the brackets are connected with tension failure plates. The corrugated sheets act like energy absorbing (EA) bellows. The EA capacities can be increased by adding collapsible stiffeners inside the box. The device is virtually evaluated in an occupant standing position in a vehicle using LS-DYNA® and LS-PrePost®. The standing occupant is modeled using ATD from LSTC. Modeling of the Gunner Restraint System (GRS) used to keep the occupant in position is developed by using Seatbelt Fitting application module in LS-PrePost. An acceleration pulse is applied to the vehicle in order to represent the effect of blast load. The EA mechanism is evaluated for various side plate thicknesses and heights of the device. The reductions in tibia force and head excursion relative to hatch are presented.