Sensitivity Analysis of Impact Properties of Ejection Seat Cushions

摘要

The sensitivity of the safety performance of an ejection seat cushion to its impact properties is defined in terms of the original, optimal, and sub-optimal performances. The analysis of this sensitivity is performed based on computational modeling and simulation. The biodynamics of an occupant experiencing an ejection event are simulated using an Articulated Total Body (ATB) model. The impact properties of ejection seat cushions are described using an expression that relates the contact force to the cushion deflection and deflection rate. The safety performance of a cushion is characterized by the occupant response characteristics, such as peak lumbar load and peak chest acceleration. The optimal and sub-optimal performances of a cushion are found through optimization. The ATB code is modified so that it can be used in optimization. The sensitivity analysis of a seat cushion shows that the improvement made by optimizing all or part of its impact properties can be significant. Improving damping and rate dependent properties of the cushion show the potential to reduce the biodynamic responses of the occupant.