Bumped Your Noggin???? Part2

[53-11]

As mentioned in a previous thread, I'm trying to put together some statistics on what parts of typical helmets are most likely to take hits. The idea is that this data will feed through to some helmet designs I'm working on right now, such that a minimum of bulk and weight can be designed in - without adversely affected the protection they give.

Although I'm just a privateer, I'm not messing about here, being in talks with a research neurosurgeon and getting concepts tested out in the digital world using a high strain Finite Element Analysis package called LS-DYNA.

So could I ask ask/plead/beg that all those who have had the misfortune of banging their heads on the ground to look at the following pictures and post up where your helmet took the hit?

And (this is maybe asking too much) if possible could you post up the maximum amount your helmet compressed versus its original thickness???

 

[Red Light]

As mentioned in a previous thread, I'm trying to put together some statistics on what parts of typical helmets are most likely to take hits. The idea is that this data will feed through to some helmet designs I'm working on right now, such that a minimum of bulk and weight can be designed in - without adversely affected the protection they give.

Although I'm just a privateer, I'm not messing about here, being in talks with a research neurosurgeon and getting concepts tested out in the digital world using a high strain Finite Element Analysis package called LS-DYNA.

So could I ask ask/plead/beg that all those who have had the misfortune of banging their heads on the ground to look at the following pictures and post up where your helmet took the hit?

And (this is maybe asking too much) if possible could you post up the maximum amount your helmet compressed versus its original thickness???

There is published research out there is you look that has already done the mapping of where helmets are hit. Unfortunately its not hit very often at the place they hit it in the tests. But then to pass certification your helmet will have to be hit in that place as well.

 

[classic33]

Where mine impacted isn't even covered in any of the above. Left ear upwards. Side impact & not covered by the design shown in your pictures.

Just noticed, you state "banging their heads on the ground". Mine was on the bonnet of the offending vehicle, that was driven into me. Does that not count. I know thin sheet steel isn't as hard as a couple of inches of tarmac, but it still wrote the helmet off, under impact rules.

 

[53-11]

Where mine impacted isn't even covered in any of the above. Left ear upwards. Side impact & not covered by the design shown in your pictures.

Just noticed, you state "banging their heads on the ground". Mine was on the bonnet of the offending vehicle, that was driven into me. Does that not count. I know thin sheet steel isn't as hard as a couple of inches of tarmac, but it still wrote the helmet off, under impact rules.

Sorry, yes - it does count.

Do you mean that my helmet in the picture doesn't come as far down as yours? If so, what point was nearest?

 

[53-11]

There is published research out there is you look that has already done the mapping of where helmets are hit. Unfortunately its not hit very often at the place they hit it in the tests. But then to pass certification your helmet will have to be hit in that place as well.

I've only seen stats for motorcycle helmets - which is similar but not directly analogous. If you come across cycle helmet research could you post a link?

 

[dellzeqq]

I split a helmet open at R3

 

[53-11]

<br />I split a helmet open at R3<br />

<br /><br /><br />

Thanks

Can I just ask though whether the foam was actually compressed at the split?

My simple engineers view on helmets splitting is that this is more likely to occur around the point of max compression where the inner surface has been unable to support tensile stresses - leading to a split in the vicinity of the area of max tension. This is what happened with my mother in laws helmet - an area of maximum compression surrounded, (in other words 'outlined') by splits on the inside of the foam.

 

[dellzeqq]

the foam was split on the inside as well - in fact, if memory serves, the split was almost as long on the inside as it was on the outside - 7 inches or so, with one side of the split being pressed inwards, putting the helmet out of shape. I don't remember it being compressed except a little bit at the outer edge of the crack - mostly it was just deformed. I hit the ground at about 22mph, cracking my pelvis as well as the helmet.

 

[hellmate]

I have taken a chunk out of L2. Many impacts on R1 and L1

 

[TVC]

First impact with the car roof was at L1, and the second impact with the road was at R2.

 

[Globalti]

I somersaulted at speed and smacked the back of my head on the pavement hard enough to leave the texture of the pavement imprinted on the helmet and the rear straps embedded into the shell. The helmet split right along the middle. I hit it on L4 and R5

 

[53-11]

Oops. I had two R5's on the back of the helmet.

Fixed Now

 

[montage]

Smashed a helmet at R5/L5 (basically the rear of the helmet)