Method for testing multi-layered cushions for certified seats 16g

摘要

The present invention is directed to a method for the certification of multilayer replacement cushions according to "16g" standard, which method comprises: subjecting cylindrical specimen of the replacement cushion and of the original cushion to a compression test to simulate the 14g down dynamic test required by FAR/CS 25.562 use the load/deflection curves obtained in a) as input to a mathematical model capable of calculating lumbar spine load; if the value of lumbar load of the original cushion is lower than a prefixed value of 6670 N as per SAE 8049A, and the replacement cushion presents a lumbar spine load lower than the original cushion, then the replacement cushion can be used without performing full seat certification. According to a preferred embodiment, the mathematical model is derived from MuSIaC (Multi Scale Impact and Crash) model, which is a multibody modeling technique for the study of the passive safety of helicopter structure in the condition of vertical impact.