Scarbs T-Tray proposal

[bill shoe]

I am really impressed by Scarbs' theory.

He brought the actual FIA load test into the picture, not just the wording of the deflection test, but rather how the loading is actually applied. He has either an intuitive or explicit understanding of free body diagrams and he applied this understanding to create the theory.

This is definitely a plausible concept for improving splitter-limited aero.

RB still seems to run their front wings lower than can be explained by their large rake.

Scarbs' theory matches the oddly long wear patterns seen on recent underbody pictures of the Red Bull splitters.

I think this is likely what RB is doing. Regardless, this is the most clever technical thing I've seen written about F1 in a while.

[beelsebob]

To be honest, what surprises me most is the FIA load test here. Why on earth are they testing the deflection in the opposite direction to the one the load is applied in during a race? Why not hook something over the top of the splitter, and then try and jack up the car on the rear of the plank and some attachment point where the front suspension meets the nose... Fail it if the height of the jacks gets above a certain limit with a certain force applied.

[simieski]

Under the rigidly secured/not having any degree of freedom rule, are the FIA not allowed to have a bit of a poke and prod at any part of a car where they suspect rules are being bent?

[dren]

So the car sits on the plank, no weight on the front or rear tires?

[xpensive]

I believe the FIA's test method for the splitter reflects the antiquated method of testing the front wing, as has been disussed earlier on another thread on F1T. With anisotropic material through clever fiberdirection lay ups, the aerodynamic load in the horizontal direction can cause just as much downward deflection of the wing as the downforce load on the same?

[hardingfv32]

This is a wonderful way around the rules and the test used to enforce them. BUT, how does this system work when the car is on track? What is providing the upward force to flex the splitter? Contact with the ground??

The plank runs to the leading edge of the splitter and is subject to wear limits. How much contact do you think they can get away with? Are we not talking about contact through most turns? Where is the plank smoke from this contact?

Even if you assume that the trailing edge of the splitter is not attached to the chassis (a “see saw” requirement?), the plank is one piece. There also is two plank mounting points located very close to the trailing edge of the splitter (leading edge of the chassis?) So now we have a piece of rock hard plywood screwed down right OVER the point of where the splitter must move downward (“see saw” effect).

It is not going to happen without a lot of force being applied to leading edge of the plank, and thus, very high wear.

I do not think this is the secret to a high rake setup.

Brian

[hardingfv32]

"With anisotropic material through clever fiberdirection lay ups, the aerodynamic load in the horizontal direction can cause just as much downward deflection of the wing as the downforce load on the same?"

This has never been demonstrated on this forum, only proposed. Can you make such a demonstration?

Brian

[xpensive]

Been there, done that, back at university in the 80s, we built cantilever beams which with the correct fiberdirection and combination of torsion- and downforce-load...bent upwards.

Saab was at the time interested in using the technology for their "Gripen" Jet-fighters, making the wings bend downwards when coming up from a deep dive, but they eventually chickened out.

[volarchico]

Similar technology is used for the X-29 to keep the ailerons from reversing.

[manchild]

viewtopic.php?f=1&t=4051&p=48922&#p48926

[hardingfv32]

xpensive, volarcgico

Is this effect linear?

Can you suggest how this would be applied to a wing to provide non linear movement?

The applications you reference talk about wing twist. I thought the goal in F1 was to get the whole wing closer to the ground.

Brian

[siskue2005]

So the car sits on the plank, no weight on the front or rear tires?

yup, thats how the plank load test is done

[timbo]

Heh, a brilliant bit in the Scarbs article

But typically the FIA rules are both vague and overly specific at the same time.

[scarbs]

For a wing, the flex doesn't need to be non-linear. Merely the axis of greatest stiffness needs to be in the same direction as the FIA load test. The FIA apply a vertical load, where as the aero load seen on track is made up of vertical and longitudenal components.
So for a drooping front wing, the endplate load test applies the force in beam bending. On track the load is torsional. So the carbon needs to be strong in beam and weak in torsion. With that information, the lay up can be influenced to provide the requisite directional strength.

[Richard]

It's more subtle than that scarbs. The vertical neutral axis would be in the same location at the FIA test, but the horiz and torsional NA will be in completely different. Then the vertical component of the aero centre of pressure is likely to be offset, resulting in torsion.

Then add in the aero horiz loads being further offset to result in more torsional forces.

The result is that one can locate the centre of stiffness in the desired location to give little defection when load is applied at the FIA location, but lots of deflection when applied at offset centres of aero pressure (horz & vert). The correct combination can cause the wing to dip up, down, forward or back - just like a puppet on a string.

hardingfv32 - yes, this can be easily replicated in any cantilever structure with asymmetric cross sections, either homogenous complex shapes (a C section is easiest) or with reinforced strands (post tensioned reinforced concrete)