Crash Testing Research

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rachaelschmitt
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Joined: Thu Feb 08, 2018 2:20 pm
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Graduation Year: 2015
Real Name: Rachael

Crash Testing Research

Post by rachaelschmitt »

Hello! I received a Student Undergraduate Research Grant in 2015 to conduct crash testing research but I don't think I ever posted the final paper here.

Note: I urge teams and Sweepstakes to interpret the test results as a single reference point that does not represent the full scope of impact scenarios or control for all possible variables. As the first crash testing study, I believe the results are incredibly informative and valuable but should not be treated as an accredited study. I encourage teams and individuals to conduct more testing so we can continue to learn and make buggy safer.

https://drive.google.com/file/d/13TpVrN ... sp=sharing

The main takeaway for me personally was:
1) We mandate harness equipment rated to 1,000 lbs but have no (at least in 2015) practical standards for the attachments points to the buggies, and those are, I believe, most likely to be the failure point of the harness system.
2) It's time to phase out forward trike buggies.

Feel free to direct any questions to me at schmitt.rachael@gmail.com., and a huge thanks to everyone who helped make the crash testing happen!
dpow
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Real Name: David Power

Re: Crash Testing Research

Post by dpow »

I spoke with various professionals who agreed that the failure point would be at the buckle or buggy attachment point, not in the webbed climbing strap used by most, or even in the stitching. To that end, I suggested to sweepstakes last year a ban on the cheap plastic buckles used by many teams, and suggested that teams swap them out with these:

AustriAlpin COBRA Buckle 7075 Aluminum Quick Release Dual Adjustable No-Sew 1.75" (45mm) https://www.amazon.com/dp/B01181DXXA/re ... FAbVGVT4SJ

I am not sure those are the very best answer, but they certainly held up to a lot more stress in my simple garage testing than the plastic "backpack buckles" that have somehow survived decades of safety chairs (myself included). The COBRA buckles were the most realistic replacement I found, because they're basically plug and play for the plastic ones. Standard automotive seatbelt buckles aren't really an option in many of the newer/smaller/tighter builds.

Also agree on a hard look at forward trikes, and braking systems in general.
shafeeq
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Re: Crash Testing Research

Post by shafeeq »

Those buckles look sweet. If both buttons have to be squeezed to unlock, then the odds of it happening accidentally while bouncing around in the buggy seem low.

I can't believe that there's a plastic buckle adequate for the forward loads. Other directions, sure, and the driver can't go very far sideways or backwards if the buckle breaks anyway. More than breaking strength, the ability to remove all slack matters in a forward trike, since there's only so much space between the driver & steering, and some of that will be consumed by the harness stretching. I'd be surprised if everyone does it well enough every single time.

The Kangol Magnet seatbelt buckle (patent 3127650) is nearly as compact. Probably hasn't been made in 40 years, but easy enough for a team to copy in-house - it's basically a flattened carabiner for webbing instead of rope and the locking function provided by a magnet instead of screw.
Pope on a Rope
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Re: Crash Testing Research

Post by Pope on a Rope »

Rather than ban wheels being positioned in front of the driver outright, I suggest a minimum distance between the front of the driver's head and any solid element that it might contact in the event of a sudden deceleration (frame, wheel, fork....). The idea is to give the harness room to work. It works by absorbing energy as it stretches. A distance of about 6 inches would work to provide that room. Might also need to specify a distance between the rear attachment of the harness to the buggy and where it attaches to the driver to provide enough webbing to get the stretch right.

Along similar lines, there should be a matching set of construction rules that do not allow any hatch element that can be removed to serve as forward crash protection (i.e. the shell or frame of the buggy needs to be forward of the driver's head and hands). It should be clear by now that hatches suck as crash protection and sleep deprived mechanics, can forget to attach them properly.

I like the look of that buckle.
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