Uni Research Project - helmets?

[Hawk]

Hi all,

I am considering hanging about university over summer to do some research. I'm an aero-mechanical engineer and regular cyclist. Research can be in any area and one possible area would be cycle helmets *gulp*

Lots of critics think that in a typical collision between head and ground, the helmet *might* do OK. But many think that as soon as you raise impact energy very slightly, the helmet cracks instead of compressing and this represents much less energy absorbed. They think helmets are "designed to compress" and cracking means they "haven't worked". I could look in to this and see what causes a helmet to crack during an impact and theoretically work out the energy dissipation in such a circumstance. I could run static testing and would likely be able to run some dynamic testing also.

People also think that at higher impact energies (e.g cyclist-vehicle collision), the helmet will do very little during the point of contact and then present a risk of snagging or causing a torsional neck injury (twisting). I could therefore look in to how much helmets tend to snag and at the torque produced by a helmet when it does snag compared to a situation where a head clips the same object but does not 'snag'.

There are other possible fields of research in this area too. However the scope of such a project would need to be well defined after looking in to budget and even time constraints.

Does anyone have any thoughts on all that, or suggestions for similar research in this field, something you've "always wondered" about, for example?

Cheers
Anton / Hawk

 

[shouldbeinbed]

All very old news, a quick search of 'Helmet' or even a trip to their very own dedicated section on here will show you that not only are we already well aware of this info, and the many projects and research papers to back up disparate viewpoints on the subject and have debated and argued it to death and back again several times over.

sorry but on the basis of this post, research doesn't seem to be a strong point

 

[Arsen Gere]

Note the tortional damage is described in some literature as the mushy brain slopping around in side a spherical skull rotating on the spinal cord in addition to the neck damage you describe.

There may be some value of a meta study in this area summarising the current literature.

One area I've not seen anything on is the combined effects of rolling resistance and wind resistance. What I mean is a 23mm tyre is often seen as having the lowest rolling resistance but when operating at 25 mph what is the impact of the aerodynamic properties over say a 20mm tyre when the part in contact with the road is doing 0mph and the top is doing 50mph?

Then there is the effect of a wider tyre on aerodynamic effects of different tyres on deeper rims.

 

[Theseus]

Stay well clear of the helmet debate.

Concentrate on the marginal gains that Team GB are interested in, like rounder wheels.

 

[Amanda P]

All very old news, a quick search of 'Helmet' or even a trip to their very own dedicated section on here will show you that not only are we already well aware of this info, and the many projects and research papers to back up disparate viewpoints on the subject and have debated and argued it to death and back again several times over.

sorry but on the basis of this post, research doesn't seem to be a strong point

Eh? Surely if there's no clear evidence to support either or any theory, more research is needed? - and should be welcomed?

It strikes me that lots of research is too narrow in scope - the 1m drop test we sometimes read about for example, isn't realistic. Or it's often argued that it isn't. What would be?

I suspect the problem may be that you could get through a lot of helmets in the course of a robust and worthwhile practical research project. Do you have a budget for this?

 

[Hawk]

Eh? Surely if there's no clear evidence to support either or any theory, more research is needed? - and should be welcomed?

It strikes me that lots of research is too narrow in scope - the 1m drop test we sometimes read about for example, isn't realistic. Or it's often argued that it isn't. What would be?

I suspect the problem may be that you could get through a lot of helmets in the course of a robust and worthwhile practical research project. Do you have a budget for this?

Totally conceptual at this stage. The last point is certainly a concern.

The thing is ofc that manufacturers don't make money from making safer helmets, they make money from making ones that are lighter, prettier and more aerodynamic.

This project would certainly be limited in scope to address one particular point such as cracking, snagging, etc.

Good question regarding what would be more realistic. Some potential there with some more thought I think.

All very old news and the many projects and research papers to back up disparate viewpoints on the subject and have debated and argued it to death and back again several times over.

Have these particular aspects been looked in to before? Not seen any studies comparing cracking vs crushing and energies absorbed, nor much on snagging.

 

[Mr Haematocrit]

The thing is ofc that manufacturers don't make money from making safer helmets, they make money from making ones that are lighter, prettier and more aerodynamic.

Think that is slightly short sighted assumption and one that is incorrect imho
If you were correct then all helmets sold in the UK would only be certified to the required standard to be determined legal which is EN1078
Specialized for example certify helmets to SNELL standard, this is a harder and more costly certification standard to meet and as such the helmets are considered safer than those only certified to EN1078.
The Snell standard has nothing to do with weight, looks or areo.. It has to do with safety

 

[dellzeqq]

I think that there's one aspect of this where you could research yourself to death, and that's the spin thing.

While I quite see that the surface of the helmet is a contributing factor, the road surface would be, surely, the greater factor. And, as we know, road surfaces vary.

I can't see how one can come to a conclusion without considering a variety of road surfaces in order that one might come up with a worst case. Equally, one could propose that a helmet that not such a good idea on a gritty road would be a boon on a smooth road. And before you know it you're in to the tarmac mix, which, may, after all, be designed to maximise adhesion.

This might be angels on the head of a pin stuff, but your choice of subject puts you at the mercy of stuff - as a read through of the helmet debates on this forum will demonstrate

 

[BigonaBianchi]

All I want from a helmet is that when my head hits the ground at 35 mph my skull doesnt implode

 

[oldroadman]

All I want from a helmet is that when my head hits the ground at 35 mph my skull doesnt implode

Which I think you may find is way in excess of the testing requirements, and as follow, the design specifications. A glancing blow, maybe, but hit anything head first at 50+kph and brain tends to become an interesting (and useless) grey soup, helmet or no helmet. Even the much higher spec moto helmets can't protect from that type of impact.

 

[byegad]

All I want from a helmet is that when my head hits the ground at 35 mph my skull doesnt implode

Sadly the best test uses 12mph. Look at the helmets mandatory in Motorcycle racing and compare to even the very best cycle helmet. Apples and very small oranges!

 

[Licramite]

yes theres four factors/injuries to consider, the lesser lacerations, fracture of the skull and compression of the brain, along with the effect on the neck.

the brain can only take 10g before it starts to get damaged - theres a load of this on a different lead - how fast does my head hit the ground if I fall off at 20mph. - but the main thing is does the foam compress before it breaks - or compress at all.
again modern helmets are not designed for low speed impacts so only really offer a hard shell that protects you from lacerations but doesn't help with concussion - as theres no foam compression.
but also are very limited on the range of high speed impacts.

Helmet design is an interesting feild with the new materials, carbon fibres, new foam materials , impact foams that crush at different rates depending on impact - as in you can push your finger into , but if you punch it , it goes rigid.

maybe a better shape the always makes impacts a deflecting blow

lots to work on.

 

[oldroadman]

yes theres four factors/injuries to consider, the lesser lacerations, fracture of the skull and compression of the brain, along with the effect on the neck.

the brain can only take 10g before it starts to get damaged - theres a load of this on a different lead - how fast does my head hit the ground if I fall off at 20mph. - but the main thing is does the foam compress before it breaks - or compress at all.
again modern helmets are not designed for low speed impacts so only really offer a hard shell that protects you from lacerations but doesn't help with concussion - as theres no foam compression.
but also are very limited on the range of high speed impacts.

Helmet design is an interesting feild with the new materials, carbon fibres, new foam materials , impact foams that crush at different rates depending on impact - as in you can push your finger into , but if you punch it , it goes rigid.

maybe a better shape the always makes impacts a deflecting blow

lots to work on.

Reminds me of a Friday night in many a town centre

 

[Mr Haematocrit]

again modern helmets are not designed for low speed impacts so only really offer a hard shell that protects you from lacerations but doesn't help with concussion - as theres no foam compression.
but also are very limited on the range of high speed impacts.

The forword to BSI Standard 6863:1987 reads as follows:
it (the standard) specifies requirements of helmets used by pedal cyclists on ordinary roads, particulary by young riders in the 5 years to 14 years age group, but which may also be suitable for off the road. it is not intended for high speed or long distance cycling, or riders taking part in competitive events.

BS EN 1078:1997 - the European standard which replaces the British Standard also make no reference towards helmets being suitable for high speed impact.

As the goal of many helmet manufacturers is to simply pass the certification required to permit sale, it would be fair to suggest IMHO that the majority of helmets sold in the UK are designed only for low speed impacts.

 

[ufkacbln]

yes theres four factors/injuries to consider, the lesser lacerations, fracture of the skull and compression of the brain, along with the effect on the neck.

the brain can only take 10g before it starts to get damaged - theres a load of this on a different lead - how fast does my head hit the ground if I fall off at 20mph. - but the main thing is does the foam compress before it breaks - or compress at all.
again modern helmets are not designed for low speed impacts so only really offer a hard shell that protects you from lacerations but doesn't help with concussion - as theres no foam compression.
but also are very limited on the range of high speed impacts.

Helmet design is an interesting feild with the new materials, carbon fibres, new foam materials , impact foams that crush at different rates depending on impact - as in you can push your finger into , but if you punch it , it goes rigid.

maybe a better shape the always makes impacts a deflecting blow

lots to work on.

I find it somewhat ironic that someone is giving advice on helmet research for a University project when their previous "scientific research" was:

Honestly try the test - no bulls*** here - its a practicle way to see if a helmets effective or not. - not made up statistics , no biased studies - its see for yourself time. you could varie the test to suit your personal take on how is my head going to the floor, you could kneal down and head but the pavement , you could try with the front, side or back of your head -

In the end you will you have a far better idea than reading every study ever done (most are utter nonesense and all are refuted with counter arguements) - so its make your own mind up, don't beleive others, don't be told things, go out and find out for yourself. - by doing it.
and yes I have tried both tests 1 and 2 (and 3 how "hard is helmet")