GT40 side impact protection

Randy V

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Okay Frank is right... My apologies for contributing to the drift...

Let's get back on track shall we?

Thanks...
 
I remember how surprised I was when I took the doors off my muscle car during restoration - they weigh almost 50 kg each! That is 50 kg of protection in the unfortunate case of an accident.
 

Randy V

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I remember how surprised I was when I took the doors off my muscle car during restoration - they weigh almost 50 kg each! That is 50 kg of protection in the unfortunate case of an accident.

Indeed this is correct. I found out back in the early eighties when I went to replace the door hinges on a friend's 1979 Pontiac Firebird with power windows.. The door had to weigh almost 200# and was a real chore to get re-aligned. :stunned:
It took two of us and a floor jack with a padded wooden saddle I made to get the door into position to where the hinges could be re-attached.. No surprise but 5 years later the hinges were worn out again.
Suffice to say - the heavier the door, the greater the impact protection.
In comparison, we are not well protected at all in these little cars..
Again, a risk that must be accepted as part of the cost of entry..
 
I drive a GTD Frame car and if you look at the frame design you are looking at setting inside a steel box that comes up to the middle of my rib cage. That's more side impact than a lot of cars enjoy.
 
One day I took the inner panel out of my CAV (broken door catch spring needed fixing) et viola, nada. Empty hole. The entire door weighs about 5lbs.

There's a bit of side impact protection in the sills but it ain't much. So, back to the OP's question........not much.
 
My RF has an anti intrusion bar in the doors. As required by our ADR's.
I will take a pic and post over the week end.
Cheers, Gus.

God bless the ANZAC's lest we forget. 100 years on.
 
Here are the intrusion bars I made.
Tubes sheeted in between and foam cored.
It is attached to the hinge and to the latch.
I have alloy doors so I made stronger bars, if you hit a tree its always going to hurt.

Jim
 

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If you were to triangulate, the triangulated members would be much longer and therefore without function (triangulation only works if you generate triangles with equal length sides).

Not true. Triangulation works because you have to have buckling of the beams for the form to deform. In the case of a square you only need the corners to deform.

You can try it yourself. Take two pieces of card, fold one three times and tape the edges together to form a square. Then fold the other twice and tape the edges together to form a triangle. Now squash them.

Anyway, back on the original thread.

I've added a 40mm x 20mm bar to the door, my doors are similar to the RCR in that they have a single bar as a hinge pin. I added a piece of tube round this, welded the intrusion beam to it (on the outer side)
20140608_171619.jpg


and then that bolts up to the lock mounting bracket. I'll probably fibreglass in the beam as well when I get to that stage.

I've also braced the sills with triangular bracing from the front inner corner to the middle of the outer. Having modelled it having a "ladder" (eg like Bob's:
attachment.php

or joining the outer and inner chassis members with any perpendicular members while it increases the amount of force required to bend the sills it transmits any force pretty much straight in and into the side of the driver/passenger. Having either no bracing between the two or diagonal means that there is a significant amount of crushable structure before the inner member starts to move.
 
Not true. Triangulation works because you have to have buckling of the beams for the form to deform. In the case of a square you only need the corners to deform.

You can try it yourself. Take two pieces of card, fold one three times and tape the edges together to form a square. Then fold the other twice and tape the edges together to form a triangle. Now squash them.

Anyway, back on the original thread.

I've added a 40mm x 20mm bar to the door, my doors are similar to the RCR in that they have a single bar as a hinge pin. I added a piece of tube round this, welded the intrusion beam to it (on the outer side)
20140608_171619.jpg


and then that bolts up to the lock mounting bracket. I'll probably fibreglass in the beam as well when I get to that stage.

I've also braced the sills with triangular bracing from the front inner corner to the middle of the outer. Having modelled it having a "ladder" (eg like Bob's:
attachment.php

or joining the outer and inner chassis members with any perpendicular members while it increases the amount of force required to bend the sills it transmits any force pretty much straight in and into the side of the driver/passenger. Having either no bracing between the two or diagonal means that there is a significant amount of crushable structure before the inner member starts to move.

Yes, squares and rectangles are prone to collapse ("fold") due to bending moments in the corners, especially if there are parallel members, which is the case for the ladder-type reinforcement posted above. The squares will, however, only fold if the outer and inner sill members can move length-wise against each other, which may not be the case. That depends on the structure on the left and right of the door sills. If the inner and outer sill members are reasonably fixed in their axial directions, the structure will fail due to buckling of the two short members that connect the inner and outer sill members.

The triangle you suggest has two very long compression members, and they can potentially fail due to buckling much earlier than the two short members in the ladder-type construction.

Of course, if the outer sill member can move length-wise with respect to the inner one, then the squares can fold.
 

Mike

Lifetime Supporter
I think a Corvette has all that plus airbags if safety is the main objective.
 
I think a Corvette has all that plus airbags if safety is the main objective.

Like I said before, you probably have a Corvette as well, and that's the main reason why I would not want one.

Also, if you're smart about it, you can end-up with side-impact protection better than that of a Corvette.
 

Mike

Lifetime Supporter
I have the gt40 but would not mind at all adding a new Z06 to the collection. Saw one the other day, great looking car. What cars do you have? Can you get a Vette down there? Maybe take a look at the new Ford GT.
 

Mike

Lifetime Supporter
With a GT40 you are so much lower than just about every other vehicle on the road that side impact is not going to be the problem. The problem will be decapitation as whatever hits you goes right up and over. I'd be more concerned with a good cage and keeping my head attached than getting punched in the side.
 
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