Investigation of vibration comfort by identification of seat transmissibility functions and tests on humans

Abstract

The improvement of vibration comfort for passengers in aircraft, railway vehicles or cars requires comprehensive analytical and experimental investigations in structural dynamics. For analytical investigations of the vibration comfort it is essential to establish suitable computational models and to validate them. The validation requires an experimental identification of the dynamic characteristics of passenger seats and persons sitting on the seats. On the other hand it is possible to directly investigate the vibration comfort by performing tests on humans. Both aspects are described and discussed here. The paper describes first the experimental identification of transmissibility functions between the floor of a passenger cabin through a typical passenger seat to the pelvis, chest and shoulder of a sitting test dummy. The transmissibility FRF were computed by using different approaches. Also, nonlinearity investigations were performed. The measured transmissibility functions can be used to validate and verify sophisticated computational models. This may lead to strong improvements in the numerical simulation and finally in a substantial progress of vibration comfort for passengers. In a test campaign with humans typical vibration test sequences of an aircraft flight were applied. It showed that that the vibration test facility, the utilized equipment and the employed tools were able to fulfill all requirements. The test facility offers the potential to perform detailed investigations of the influence of vibrations on passenger comfort up to 100 Hz which is impossible with most standard vibration simulators.