According to a certain type of aireraft fuselage structure's crashworthiness(occupant survivability envelope) design requirements

a standard 14

g

vertical impact test of the 'floor-seat-occupant' system which meet the requirements of AC25.562-1B regulations was carried out first. Then

finite element model calibration of the test was carried out based on Ls-Dyna software. After calibration

in order to simulate the vertical drop conditions

several impact pulses with different peaks and widths were designed

calculated and tested on 80° fixture condition

and obtained the seat vertical impact pulse envelope meeting the occupant lumbar injury index

which provide reference for the desig

n of aireraft fuselage structure. In addition

the concept of seat 'force transfer coefficient K' and the hysteretic effect of seat cushion on passenger lumbar load under different impact pulses were proposed based on the injury index of passenger lumbar load.