Modeling Framework for Automated Aircraft Escape Injury Risk Assessment

ABSTRACT: ATA Engineering, Inc. (ATA), partnered with L-3 Applied Technologies Inc. (L-3 ATI), proposes the development of configurable models, a simulation framework,and a software interface that will augment biodynamic experiments to provide stakeholders with a screening tool to quickly evaluate injury likelihood given a set of ejection system and occupant parameters. The effort will leverage decades of company experience performing advanced finite element (FE) simulations to create a configurable model of the F-35 ejection equipment (seat, guide rails, cushion, restraints, and flight gear) and methods for applying the governing forces (ejection, gravitational, aerodynamic [windblast], and parachute [drogue and main]) to the model. Using the commercial analysis software LS-DYNA, the component mechanical finite element models (MFEMs) will be coupled with an existing human finite element model (HFEM) developed by L-3 ATI to enable rapid assessment of injury probability and severity. In Phase I, the project team will demonstrate feasibility by creating a functional user interface mockup, integrating mechanical and biodynamic models, executing a simulation of a test rig acceleration event, and comparing the predicted response to measured ATD data. Phase II will involve model refinement, flight load modeling,and preliminary validation using measurements from rocket sled testing of the F-35 seat.; BENEFIT: Including the U.S. Air Force and Navy, F-35 fleets will soon become part of at least thirteen international forces. While component commonality across all F-35 variants (A, B, and C) promises to achieve efficiencies in procurement and sustainment, the aircraft will ultimately fulfill vastly different roles for each operator. In addition, the flight suit equipment, restraints, helmet configuration, and even average pilot sizeall critical factors in injury riskwill undoubtedly vary across these operators, even as the US16E ejection seatremains common. While rocket sled testing will provide some in situ measurement of the loads imparted on the occupant, it will not account for human responses (e.g., pre-ejection bracing) and will only be performed for a small subset of conditions. As a result, the proposed tool will be critical for giving stakeholders responsible for ensuring pilot safety, including Martin-Baker and AFRLs Human Effectiveness DirectorateApplied Neuroscience Branch (RHCP), a means for comprehensively evaluating injury risk across a wide parameter space of equipment and escape condition permutations. As the F-35 ejection system and pilot equipment continue to evolve, ensuring pilot safety will be of paramount importance to the Joint Program Office (JPO). The tool will also aid escape injury assessment for future aircraft, such as the Long-Range Strike Bomber and Trainer-X (T-X), which will have unique flight envelopes.