They crack like egg shells..
Discussion
Fibreglass and GRP (Glass Re-enforced Plastic) are actually incredible materials for crash protection. You actually get two key benefits for the use of Fibreglass or GRP:
1) Absorbion - The impact is absorbed by the bodyshell and then transmitted across the whole panel (in the case of a TVR its the whole body). Rather than just crumple, they transmit the impact across the section and thus disipate the impact. Should the impact be great enough it will then crack and shatter, further disipating the impact damage.
2) Resistance - GRP and Fibreglass are excellent at resisting damage and impact. This is at much higher speed than metal and thus less likely to damage.
All in all GRP and fibreglass bodies have a greater crash impact ability than an equivalent metal bodied car. The fact that the GRP is wrapped around an ultra-strong steel chassis has nothing to do with it I suppose!!! Dont forget that the Griffith and Chimaera have chassis derived from the Tuscan racer, which has proven many-a-time to be massively strong....
To be honest I trust a separate chassis structure to that of some monocoque one. Take thin metal (steel or aluminium) and bend it into shapes to give it strength...? Nah, give me stonking great steel tubes any day....
Oh, and a GRP crashed car might look bad, but it usually isnt. It takes specialist repairs, but to be honest its actually cheaper and better to repair than metal - cos you can replace whole body sections with the same strength it had originally, while metal is permanently weakened once you bend it.....
And NO they dont break like egg shells..... as already commented, crash helments? Metal are they?
1) Absorbion - The impact is absorbed by the bodyshell and then transmitted across the whole panel (in the case of a TVR its the whole body). Rather than just crumple, they transmit the impact across the section and thus disipate the impact. Should the impact be great enough it will then crack and shatter, further disipating the impact damage.
2) Resistance - GRP and Fibreglass are excellent at resisting damage and impact. This is at much higher speed than metal and thus less likely to damage.
All in all GRP and fibreglass bodies have a greater crash impact ability than an equivalent metal bodied car. The fact that the GRP is wrapped around an ultra-strong steel chassis has nothing to do with it I suppose!!! Dont forget that the Griffith and Chimaera have chassis derived from the Tuscan racer, which has proven many-a-time to be massively strong....
To be honest I trust a separate chassis structure to that of some monocoque one. Take thin metal (steel or aluminium) and bend it into shapes to give it strength...? Nah, give me stonking great steel tubes any day....
Oh, and a GRP crashed car might look bad, but it usually isnt. It takes specialist repairs, but to be honest its actually cheaper and better to repair than metal - cos you can replace whole body sections with the same strength it had originally, while metal is permanently weakened once you bend it.....
And NO they dont break like egg shells..... as already commented, crash helments? Metal are they?
Paul, I don't know about the crash characteristics of GRP bodies in general, but I'd guess that a monocoque structure made from an elastic material like (sheetmetal-) steel behaves better in terms of crumpling at higher speed (30kph+) impacts, than an inflexible bolt-on shell. Not that I think steel frame cars are unsafe in general, but I wouldn't like to have a crash in my Landrover, since the ladder frame would crumple heck all in case of a survivable impact.
Should an imapact build up forces that crumple the steel frame, my body would already been accelerated to a point where it does the crumpling itself.
Should an imapact build up forces that crumple the steel frame, my body would already been accelerated to a point where it does the crumpling itself.
los angeles said:LA, I can only recall one Ferrari model made of plastic material, and this is the first series 308 GTB with carbs. The material used is usually classified as Vetroresina, which must be some sort of reinforced plastics.
... And let's not forget half the great sports cars in the States are made of GRP, Viper the most recent, and hey, a good few Ferraris too!
The other good few might be replicas of other models with plastic body.
Bodo said:
Paul, I don't know about the crash characteristics of GRP bodies in general, but I'd guess that a monocoque structure made from an elastic material like (sheetmetal-) steel behaves better in terms of crumpling at higher speed (30kph+) impacts, than an inflexible bolt-on shell. Not that I think steel frame cars are unsafe in general, but I wouldn't like to have a crash in my Landrover, since the ladder frame would crumple heck all in case of a survivable impact.
Should an imapact build up forces that crumple the steel frame, my body would already been accelerated to a point where it does the crumpling itself.
Absolutely Bodo - steel does have significantly better deformation characteristics than GRP and it will always will. The big difference is that steel bodied cars are designed to deform - safety cell and all of that. The problem with the deformation is controlling it - where to direct the force, what can deform and where will it go.... this is something that many manufacturers are still struggling with.
In fact one of the biggest problems with steel bodied monocoque cars is the do deform. You want some deformation at first and then you want to disipate the energy through the body shell - preventing too much damage getting to the safety cell etc. Just how many stories have you heard of someone with smashed knees from a head-on smash? Deformation continues due to the impact speed and forces the engine back - into the driver / passenger..... A separate chassis is a non-deformable element of a car which is supposed to prevent this from happening....
Its all about two ways of doing the same thing - surviving a big smash. Take a look at the latest NCAP 5* cars and they are amazing. Consider an MGB in a similar smash - doesnt bear thinking about really. Like you mentioned, once you start getting upto serious speeds of impact you are looking at other factors in injuries - decelleration, seatbelt, airbag, steering wheel, whiplash etc.... deforming bodyshells arent going to save your live per se....
I dont believe a GRP bodied separate chassis car is any worse or better than a well designed monocoque bodyshell - both have different characteristics and both do their job very well..... I just hope that no-one has to try it out in the real-world.
Having walked away without a scratch from a front/rear impact into trees, I can testify for the strength of the design - not sure if I'd have been so lucky if I'd gone in sideways though. (zero side-impact protection). Car was Cat C, I'm hoping someone has the heart to resurrect her...
LA, my name has teutonic origins and so have I. yours sound Hispanic 
I've just remebered that the F40 (+successors) has a carbon fibre monocoque, and some carbon fibre panels (?). At least the panel below the rear clamshell is made of GRP; but I think GRP covering panels are common to later Ferrari ref.
I've just remebered that the F40 (+successors) has a carbon fibre monocoque, and some carbon fibre panels (?). At least the panel below the rear clamshell is made of GRP; but I think GRP covering panels are common to later Ferrari ref.
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