In order to investigate human dynamic response to impact, six subjects were exposed to vertical impact in sitting position. Levels of impact were about 3, 5, and 10G. Each subject was exposed to four impacts in each level of G within an interval of about half an hour. 11 monkeys were subjected to 1 approx. 50G impacts. Each monkey sustained 16 approx. 24 blows within about an hour. The acceleration of impact carriage, the seat, and different parts of the human and monkey bodies were measured. Positive correlation were found between peak accelerations of the seat and corresponding peak responses of the human and the monkey bodies. The transfer function indicated that human body responds to impact as a whole, and the response frequency is affected by the level of impact. Human resonance frequency decreased with the increase of impact G, but the amplitudes of the second peak increased, and the frequency band became wider. Such results were similar to human vibration responses. Human responses to both impact and vibration seem like a nonlinear spring system, and it also seems that a nonlinear equation is more suitable for such a system. In general, a nonlinear system may be approached by sectional linearization. Basing on that the rule of response of human body is clear and that there are different main peaks in response to vibration and impact, the use of different one-degree-of-freedom linear models for predicting human responses is recommended. Methodology of study on dynamic response to impact was also discussed.
|Original language||English (US)|
|Number of pages||6|
|Journal||Hangtian Yixue Yu Yixue Gongcheng/Space Medicine and Medical Engineering|
|State||Published - Dec 1994|
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