Is there someone we can engage to do some preliminary math, to help us understand the loads and forces involved? Seems like it shouldn't be too hard to figure that in an impact resulting in XX g., offset at X*, the net has to catch XXX pounds of noggin...
Yes, that part is rather straightforward:
mass = adult male head + helmet = 8 to 12 pounds + 2.5 to 4 pounds = ~ 15# to use a round number on the high end of the spectrum,
acceleration = 50Gs? 70Gs? 100Gs? Nets have been tested at 50Gs, so let's go with that.
f=ma = 15# x 50Gs = 750#.
(This assumes the upper body is contained at the shoulder, so only the head loads the net.)
The interesting math probably happens at the mounting points. I remember a college engineering problem that asked why a fraternity party organizer could tear the wall off of a house, trying to lift a beer keg off the ground in the middle of a horizontal cable between said house and a huge tree, suspended 5' off the ground and tightened with a come-along.
Yup, the same loading diagram.
...and if I understand what I was told about mounting right side nets, one function is potentially very particular about mounting: That of keeping the helmet between seat side restraint wings on REBOUND. Having the net really close to said wings seems crucial, so maybe we can research and relay some guidance to installers, in addition to being a clearinghouse for performance data.
The test should require that the net be mounted "according to manufacturer's instructions". You may need to add some connector/webbing at each connection point to represent a typical installation.
Nets have broken in previous tests, so a good place to start would be a single load to failure test, i.e. mount the net in a frame and push on it until it breaks. The failure load would imply a G limit.
