Chassis Improvements - Grosjean accident

[PlatinumZealot]

Hey, guys.


So I was thinking about how Grosjean's car was separated by the rails (blades?) of the Armco barrier as the car penetrated it and the resulting punctures / cuts / tears in the fuel system. I am not apportioning blame to the barrier or the car in this topic, everything can be improved so it would be due diligence to look at the car as well. Here is to discuss the car.


These questions come to my mind:

Stonger Engine to Monocque coupling

What if the Engine, which is a load bearing segment of the chassis, did not separate from the monocoque?

Why did it happen and should we prevent it from happening in this case?

How can this be done?

A layered metal or zylon band surrounding the fuel tank connection area to prevent cuts and punctures?

How did the fuel system get breached? The dry break connections supposedly did their job at least from the engine side, but there was a signficant amount of fuel realeased from somewhere. Whether or not it was a continued leak or not it hard to tell.

Would Zylon layers have prevented these cuts/ slicing or tank or fuel connections or lines?

Feel free to reflect and discuss.

[Shooty81]

Was it the fuel tank bursting? Or the batteries burning through it?

[1158]

The fuel cell was not compromised. It sounds like it was the collector.

http://www.gptoday.com/full_story/view/ ... eans_life/

[SiLo]

You want the car to break in half, it dissipates energy quite well making it safer for the driver. The safety cell absolutely did it's job, it was still in tact and the driver was ok, halo did it's job too.

I think the bigger thing to investigate is the barrier used in that location, and the fuel issue. Stopping fuel leaks will probably be the main working point, and then ensuring all barriers are correctly designed.

[jjn9128]

Without having the data at hand it's tricky to say anything. What is clear is that there are certainly things the fia will learn - barrier being penetrated, fuel cell being compromised.

It looked to me like the front half chassis stood up fairly well. Though there was a crack along to top across from the halo mounting point. This stopped at the side reinforcing panel so maybe there will be a requirement to reinforce around the halo bracket with xylon in future.

The rear of the chassis looks like half of the engine studs pulled out but the other half ripped away the rear of the chassis exposing the fuel bladder. Either the compression or tension side pulled out I can't remember from the image. There is also on the side which was compromised a missing cap for the fuel filler/ breather pipes. This side looks like it was subject to greater burn intensity than the other side of the chassis. So it looks to me like this is the cause of the fire rather than the bladder surface being breached.

There's a question of how to do this without adding weight and adding more energy to future crashes. I think f1 is too fast/corners too fast in the modern formula.

[Jolle]

one way to go with improving the chassis is to strengthen the connection between and the tub. A better option maybe to have the engines bolts to be just that tiny bit weaker then the backside of the tub, so if there is some strange force on there, the bolts (and seal off fittings for fuel) will snap before it rips the carbon tub.

Looking at pics of the rear of the tub on the crane, it seems that the bladder stayed in tact) bit like when in the early nineties that Lotus split in half). A redesigned system for fuel outside of the tank (which will already be going down from 2 liters to just 0.25 liters) would help a lot.

[LM10]

You want the car to break in half, it dissipates energy quite well making it safer for the driver. The safety cell absolutely did it's job, it was still in tact and the driver was ok, halo did it's job too.

I think the bigger thing to investigate is the barrier used in that location, and the fuel issue. Stopping fuel leaks will probably be the main working point, and then ensuring all barriers are correctly designed.

Wanting the car to break in half makes sense. The effects of that 53g impact would have increased the likeliness of losing consciousness or even a brain trauma in a significant way. I was hugely surprised, but equally happy that it didn't happen anyway when thinking of the deceleration he went through which should have lead to his brain moving in the skull causing what's called a deceleration injury.

[Hoffman900]

You absolutely want the car to break in half. That's a good thing. You also want the the fuel cell to go with the rear half, not the driver's half. Indy Car figured that out a while ago and they routinely have impacts much more severe than Formula One.

[Big Tea]

While there is always room for improvement, TBH I am impressed with how well it worked. They would have to be very sure any alteration would definitely be for the better, because as they say- if it aint broke dont fix it.

Anything should be taken on board though, from any accident.

[PlatinumZealot]

one way to go with improving the chassis is to strengthen the connection between and the tub. A better option maybe to have the engines bolts to be just that tiny bit weaker then the backside of the tub, so if there is some strange force on there, the bolts (and seal off fittings for fuel) will snap before it rips the carbon tub.

Looking at pics of the rear of the tub on the crane, it seems that the bladder stayed in tact) bit like when in the early nineties that Lotus split in half). A redesigned system for fuel outside of the tank (which will already be going down from 2 liters to just 0.25 liters) would help a lot.

Since the bladder is pretty much enclosed and protected by the monocoque, perhaps the fuel collector should be placed in an enclosure attached to the monocoque with only dry break lines poking out... Should reduce the risk of puncturing the collector.

[PlatinumZealot]

You absolutely want the car to break in half. That's a good thing. You also want the the fuel cell to go with the rear half, not the driver's half. Indy Car figured that out a while ago and they routinely have impacts much more severe than Formula One.

Yes. This makes a lot of sense.. but know you are talking about a fundamental redesign! A two peice-monocoque! Driver cabin plus Fuel carriage... that would be quite an interesting design.. much longer that is for sure. Two sets of couplings, engine to fuel carriage to cabin.. Torsional rigidity would need to be addressed.

[Jolle]

You absolutely want the car to break in half. That's a good thing. You also want the the fuel cell to go with the rear half, not the driver's half. Indy Car figured that out a while ago and they routinely have impacts much more severe than Formula One.

You don’t want the car to spit in half! Having an impact with a 250 kg mass or a 800 kg makes a big difference in the type of structures around the track. You want big impacts take as long as possible to have the lowest G’s possible.

What you want is if the impact so high or on a weird angle that the car will break apart, it’s done in a controlled manner, not like with Grosjean, where it took pieces of the tub with it.

[Ringleheim]

When I first immediately saw the impact and fire, and the way in which it wasn't flashing out very quickly, I thought: "That's crazy; I bet the engine has somehow become disconnected from the chassis" and that's exactly what happened, although we had no idea of the details at that point.

This accident is incredibly similar to the one that killed Francois Cevert at Watkins Glen in 1973.

It is not very similar to Martin Donnelly's terrible crash (referenced during telecast by Brundle) in that Martin's Lotus chassis *ITSELF* broke in half around the area where the driver sits.

Grosjean's accident was more common; there are only 6 bolts holding the engine onto the back of the monocoque and it is designed that way for a reason.

The car worked well overall in the crash I would say and the HALO may have saved his life.

The flaw in the system here? The armco guardrail. It shouldn't be used anymore.

[NL_Fer]

Maybe they should have another think about those barriers in front of the escape area. This part was angled towards the track to have an opening for cars to be removed. No more plain barriers for those parts.

[Big Tea]

When I first immediately saw the impact and fire, and the way in which it wasn't flashing out very quickly, I thought: "That's crazy; I bet the engine has somehow become disconnected from the chassis" and that's exactly what happened, although we had no idea of the details at that point.

This accident is incredibly similar to the one that killed Francois Cevert at Watkins Glen in 1973.

It is not very similar to Martin Donnelly's terrible crash (referenced during telecast by Brundle) in that Martin's Lotus chassis *ITSELF* broke in half around the area where the driver sits.

Grosjean's accident was more common; there are only 6 bolts holding the engine onto the back of the monocoque and it is designed that way for a reason.

The car worked well overall in the crash I would say and the HALO may have saved his life.

The flaw in the system here? The armco guardrail. It shouldn't be used anymore.

I think donnoly was a different case. He was left sitting on the track and none of the car around him.
It was not designed to break in a particular, just made as light as possible.
There was no thought at all for driver protection.

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