Vibration/Impact causing falling /tripping

[ariky]

Hi everybody,
I'm looking for data about which this issue.
For example, a person is standing on the a mobile crane chassis while at operation (the vehicle itself is stationary but the upper structure, boom etc. moving or rotating). What kind of vibration or sudden impact/movement will cause him to loose its stability and trip/fall.
Thanks,
Ariky

 

[alexit]

I guess at this, but 0.1-0.2 g acceleration would cause to loose balance...maybe check nasa documents for human acceleration limits?

 

[GregLocock]

You will need a third derivative of displacement (jerk) rather than acceleration. Human beings can cope easily with relatively large accelerations, where they stumble is when that acceleration CHANGES.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[JeanMicheling]

When I was at the University, we did a study for a security firm about the security relating a stepladder. We fixed a rigid cable to the stepladder while a guy (I was the lucky one) was standing on a step securely attached. We dropped different weights (fixed to the wire) at the same height until the guy falls. Unfortunately, I no longer know where this study is but maybe it can help you finding a solution to your problem. Of course, you guessed that knowing the weight and the height, you can evaluate the acceleration produced on the ladder to cause the guy to fall.

 

[amorrison]

This article and/or the references at the end might be useful for google search buzzwords.

http://www.smpp.northwestern.edu/

~smpp_pub/PattonPaiLeeEBR2000.pdf