Scuderia Toro Rosso STR5 Ferrari

[Pandamasque]

Nice shot of the holes there.

Also is that 'pull rod' suspension?

Yes. Both Red Bull teams retained it since last year.

[autogyro]

This one looks like last years, the RB6 is way different.

[Shrek]

Does anybody know what exactly happened to Buemi's suspension, because i saw on the replays that his left front had a broken front part of the wishbone while i saw his right front go straight up and they both happenned within a split second?

edit :I looked at another one at a different replay and it was actually the right front wishbone broke first

[Pedro]

Does anybody know what exactly happened to Buemi's suspension, because i saw on the replays that his left front had a broken front part of the wishbone while i saw his right front go straight up and they both happenned within a split second?

edit :I looked at another one at a different replay and it was actually the right front wishbone broke first

It was not the wishbone but the upright failure:


Video:
[youtube]http://www.youtube.com/watch?v=s27hoxjE ... r_embedded[/youtube]

[zgred]

[marcush.]

excuse me ,where is the wheel teether ??? and to what part is it attached?
the failure seems to be the top attatchment -steering arm -broke away complete with
the top of the upright...the damaged upright looks a like a toy compared to the part pedro showed in his post or is this just the camera angle?

[Shrek]

I was half right, according to zgrd's picture.

[autogyro]

I hope this has nothing to do with any attempt to change suspension actuation in a search for ride height control!
Other than altered forces of some magnitude in that area, I can only think that it is a major materials fault. It is far more likely an altered force cause if both sides went together.

[tommylommykins]

So what would cause such a catastrophic failure as this? I guess the original cause of the failure must have been in the brake caliper, because there is no other part in the wheel hub which could create enough force/energy to rotate the hub off the suspension arms...

There is a lot of energy in a rotating wheel; I've seen videos on youtube where open wheelers have shed a wheel, which has then carried on to the end of the straight, hit the wall, flown 100 feet over the grandstands and landed on some unfortunate person's car on the far side of a the carpark... If the brake calipers snapped shut and tried to freeze the wheels semi-instantly, I would imagine there was enough oomph there to cause destruction

But if so, why would the brakes activate so explosively like that? What actual mechanism would cause it? Presumably the pressure created on the disk by the calipers is proportional to the pedal travel? Would Buemi have had to push the brake pedal past the nose of the car to get that much effect? What about the fact that the driver cannot instantly apply high amounts of pressure to the brakes when pressing the brake pedal? Is the time it takes to push the brake pedal down enough to mean that it should not be possible to snap the braked on like this?

Of note is the fact that the wheels bounce upwards after the suspension arms break.. What can we read from this? Is this just because the downforce from the car is no longer being applied to them so they bounce up? Or is it because whatever rotation during the failure also pushed the wheels a bit down.. Can we take this as an indication that the failure was due to a problem in the brakes, rather than something stranger, such as weird vibrations or resonance causing the wheels to rattle off the suspension?

ALso, out of curiosity, what is the material that the brake discs are made of?

[Pit]

ALso, out of curiosity, what is the material that the brake discs are made of?

All the teams currently use carbon fibre composite brake discs.
I believe the failure wasn't caused by the brakes themselves. It somehow resembles Virgin's front wing problem, which they encountered back in winter testing.
I think that after Buemi had pressed the brake pedal, the load on the front wheels was at its peak, as the weight "shifted" to the front. STR engineers might have underestimated the forces that are present in such conditions, and therefore their suspension wasn't durable enough to withstand them. Just a wild guess but hey, we'll never be sure

[autogyro]

I am pretty certain of at least two things.
One, it was not the brakes, they must be capable of locking the wheels up at any speed without this type of failure.
Two, it was not a materials fault, the chances of both sides at once is almost impossible.

[ringo]

The brakes were applied before the suspension broke, I agree the brakes were fine.

I think Buemi was on the brakes, then the wheel hit the bump. Since for the instant the wheels are in the air the wheel is locked, the locked wheels came down on the bump with the momentum and energy of the whole car. The bump rotated the wheel and upright, turned some of this energy into strain energy in the wishbones; wishbones fail at the joint; and this strain energy was released in what seemed to be an explosion.
The geometry and material of the upright may have been the problem. I guess it wasn't designed for ramming into bumps.

[RacingManiac]

When you are designing the upright, the peak loading condition is likely to be underbraking and bump at the same time. F1 car generates 5+G of decel under braking, that is a tremandous amount of load being applied almost in the form of an impact load by itself with bump it'll be even more. It may just be that the version 2 of the upright was opimized more for weight(reduced factor of safety maybe?), and it was just underestimated for the condition.

STR says the right one failed first, and pretty much the moment the right one failed the left one is overloaded instantly and failed too...

[PlatinumZealot]

The failiure looks like a brittle failure. The material looks like a very stiff material and it definitely reached it's ultimate tensile stress. Looks like a fracture that propagated across the the object.

Reminds me of a river stone.

[alexbarwell]

Sounds a bit like a manufacturing/installation fault as failing after the relatively few laps for testing is nothing compared to hammering round the track for a full race distance - it should last at least 50 laps, not half a dozen...