Rear wing flex and FIA regulatory test 2021

[DChemTech]

Not really, because the wing was only explicitly illegal due to a change in the rules (in particular, the rules that state the allowed tolerances for flexing) in the middle of an ongoing season. You cannot blame really blame a team for having a car that was designed based on tolerance A, for not abiding a tolerance B that was never specified when they were designing it.

It's like saying that it's the waiters problem that you got a medium rather than a rare steak, while you never specified that you wanted rare in the first place.

[RZS10]

That video doesn't mention any time frame for any part so i don't understand where the assumption comes from that four weeks wouldn't be enough?

[Jolle]

Not really, because the wing was only explicitly illegal due to a change in the rules (in particular, the rules that state the allowed tolerances for flexing) in the middle of an ongoing season. You cannot blame really blame a team for having a car that was designed based on tolerance A, for not abiding a tolerance B that was never specified when they were designing it.

It's like saying that it's the waiters problem that you got a medium rather than a rare steak, while you never specified that you wanted rare in the first place.

That’s not entirely the case. The rules weren’t changed, the way it’s enforced is.
The rule (in bigger wording) is that parts on the unsprung parts of the car should be rigid. Because no material is 100% rigid there is, just like every measurement in the car a tolerance is set. A wing that bents for aerodynamic purposes is, in that case illegal.

[DChemTech]

Not really, because the wing was only explicitly illegal due to a change in the rules (in particular, the rules that state the allowed tolerances for flexing) in the middle of an ongoing season. You cannot blame really blame a team for having a car that was designed based on tolerance A, for not abiding a tolerance B that was never specified when they were designing it.

It's like saying that it's the waiters problem that you got a medium rather than a rare steak, while you never specified that you wanted rare in the first place.

That’s not entirely the case. The rules weren’t changed, the way it’s enforced is.
The rule (in bigger wording) is that parts on the unsprung parts of the car should be rigid. Because no material is 100% rigid there is, just like every measurement in the car a tolerance is set. A wing that bents for aerodynamic purposes is, in that case illegal.

But the rules didn't (and AFAIK, still don't) specify any "measurement-independent" tolerance. There is no "maximum X mm/Y degrees deflection/rotation under any circumstance" or so specified. The only specified tolerances are those related to the test conditions. So, by changing the test requirements, inherently the tolerances are changed - and teams are forced to abide to regulations that they were not aware of when making the initial design.

Now, the FIA has the right to do that (although IMO they shouldn't - they should come up with clear, test independent tolerances before a season starts), but one cannot state the RB wing was illegal under the old regulations. It was made illegal by a sudden regulation change. For the future, I do hope FIA will add an unconditional tolerance specification such as a maximum deflection under any circumstance, or at least a clear extrapolation of the test conditions to track conditions.

Of course, the situation is different if there was some deliberate spring mechanism, or pseudo-DRS like 'sudden yielding' under driving conditions that was not present in the test - that would amount to an illegal confrontational change, rather than the natural flexing under load of a material.

[PhillipM]

That last paragraph is exactly what they suspected was happening. The wing was much more rigid up to tests loads than it was after that as parts deliberately deflected to reduce the stiffness.

Which is deliberate design for aero elasticity, which is where the grey area comes in and why the FIA clamped down.

[DChemTech]

That last paragraph is exactly what they suspected was happening. The wing was much more rigid up to tests loads than it was after that as parts deliberately deflected to reduce the stiffness.

Which is deliberate design for aero elasticity, which is where the grey area comes in and why the FIA clamped down.

For such reasons some statement on extrapolation of test conditions would be very valuable. A literal lever that yields above a certain load is pretty cut-and-dry, a designed non-linear response without a true confrontational change is, as you say, a pretty grey area. There's no statement in the current rules that non-linear behaviour is forbidden, and earlier discussions in this thread were about some non-linearity being pretty much inevitable... but where do you draw the line?

FIA could easily write something down like "a maximum deflection of X under load Y, and not exceeding a linear extrapolation of aforementioned deflection under higher loads" or so, and that would resolve it. Even if the behavior is non-linear, the engineers know what maximum to design for under all circumstances (the other option would be the before-mentioned unconditional maximum deflection). By just changing tolerances, they may have reduced the freedom to exploit the grey area a bit, but haven't removed the grey area itself... patchwork symptom relief rather than a real cure

[PhillipM]

I mean the problem is, as soon as you start designing that in, that's against the rules, because you're deliberately designing flexing bodywork for aero gain, whilst compromising the structural side, you can't argue that you're just designing a structure to the minimum weight/stiffness to meet the tests any more.
Proving that however, is incredibly difficult for the FIA without some insider documentation which you can bet the teams are very careful to make sure the flexing is 'incidental' and just as a result of their software optimisation and refinements rather than an outright decision.

The only way around that is to alter the tests. Or rewrite the regulations. No point having a rewrite when everything changes next year, so you change the tests to clamp down on it.

[nzjrs]

That last paragraph is exactly what they suspected was happening. The wing was much more rigid up to tests loads than it was after that as parts deliberately deflected to reduce the stiffness.

Which is deliberate design for aero elasticity, which is where the grey area comes in and why the FIA clamped down.

Wasn't this the whole schamoozle we went round and round the roundabout on with dans79 with 'deliberate' being coded language for intent, which either was or was not the most important aspect of enforcing the rules, depending on the rules of course.

My point being that down that way lies another fractal layer of madness, so eventually for sanity you regress back to the test being the embodiment of the rules.

This is of course not a theoretical sport, but an embodied one.

[Stu]

That last paragraph is exactly what they suspected was happening. The wing was much more rigid up to tests loads than it was after that as parts deliberately deflected to reduce the stiffness.

Which is deliberate design for aero elasticity, which is where the grey area comes in and why the FIA clamped down.

Wasn't this the whole schamoozle we went round and round the roundabout on with dans79 with 'deliberate' being coded language for intent, which either was or was not the most important aspect of enforcing the rules, depending on the rules of course.

My point being that down that way lies another fractal layer of madness, so eventually for sanity you regress back to the test being the embodiment of the rules.

This is of course not a theoretical sport, but an embodied one.

Exactly! With the computational power available along with FEA analysis of carbon layups the designers are almost pushed into using the testing tolerance as a parameter.
This is using the test regime to embody the rule (just the same as suspension members have dimensional constraints applied as they are intended to be aero-neutral in the regulations).
No team would be able to build a car anywhere near the weight limit if the i spring parts of the car were designed to letter of the regulations.
I am still very surprised that no team suggested that T-wings be taken into account for flexing - they exist in a very small regulation box, but when they flex and vibrate do they do so enough to exist outside of the regulatory box?
This would also be a direction that could have been taken with both front ant rear wing deflection, the dimensional boxes that these exist in are measurable statically (even when the testing loads are applied).

[dans79]

That last paragraph is exactly what they suspected was happening. The wing was much more rigid up to tests loads than it was after that as parts deliberately deflected to reduce the stiffness.

Which is deliberate design for aero elasticity, which is where the grey area comes in and why the FIA clamped down.

Wasn't this the whole schamoozle we went round and round the roundabout on with dans79 with 'deliberate' being coded language for intent, which either was or was not the most important aspect of enforcing the rules, depending on the rules of course.

My point being that down that way lies another fractal layer of madness, so eventually for sanity you regress back to the test being the embodiment of the rules.

This is of course not a theoretical sport, but an embodied one.

Yes and no, the FIA uses simple tests, because Thursday inspections would take absolutely forever if they had to do everything as stringently as possible.

Thus the FI uses a series of simple tests and measurements to determine if a car is "within the spirit of the rules” and can be raced. Overtime as teams push the limits of the simple tests the FIA will change the rules or the tests or in some cases both.

[RZS10]

Ferrari, Spain (old test, bottom) vs. Hungary (new test, no tolerance, top), both highDF wings:

Full image, source visible


RedBull, Baku (old test, bottom) vs. Silverstone (new test, no tolerance, top)


It would appear that there's less flex in both cases.

[peaty]

I mean the problem is, as soon as you start designing that in, that's against the rules, because you're deliberately designing flexing bodywork for aero gain, whilst compromising the structural side, you can't argue that you're just designing a structure to the minimum weight/stiffness to meet the tests any more.
Proving that however, is incredibly difficult for the FIA without some insider documentation which you can bet the teams are very careful to make sure the flexing is 'incidental' and just as a result of their software optimisation and refinements rather than an outright decision.

The only way around that is to alter the tests. Or rewrite the regulations. No point having a rewrite when everything changes next year, so you change the tests to clamp down on it.

As many have point out before, bodywork flexibility is allow within the rules. So no, you're not againts the rules (as long as you're within articles 3.8 and 3.9 I must say). The only thing that the FIA can do is changing the amount of flexibility that is allow (article 3.9.9).

Again, you cannot enforce a rule that doesn't exist, and that includes the spirit of the rules (that all be said, comes and goes when it suits someone).

Designing flexible bodywork doesn't neccesarily means compromising the structural side. And yes, you still can argue that you're just designing a structure to the minimum weight/stiffness to meet the test although you don't have to.

Look at it this way, every single rear wing flexes, hence every single team is gaining an aerodynamic advantage. If that is against the rules, why those wings still legal?

We still have the exact same scenario than before the tests were changed. All rear wing flex, some do so more than others but all of them are within the rules. In other words, the new test introduced had nothing to do with the technical side. It was purely politics. The right thing to do in that case was just conducting a test base on the rules and, if it pass (which they did) it's legal! It's Mercedes fault if they are not extracting the maximum from the regulations, not the other way arround.

If the FIA consider, as they did, that a new test should be introduce because the regulations were obsolete (I'm not sure, but I think article 3.8 and 3.9 are pre-2017, I mean to say those article are exactly the same as they are now)...they should update both articles completely, not just single elements as they have done. Specially when it's pretty clear that other elements in the cars are flexing. Otherwise their credibility would be question, even more so when there are footage of those element flexing and this is the last season with the current regulations.

[El Scorchio]

Is there any point in reviving this argument? because that's basically all it is.

It's done and dusted. The reg changed happened a couple of months ago, there's been barely a peep more out of anyone in the sport about it, and they are not currently looking at front wings or any other parts of cars. There's nothing more that can be added, other than more pontificating, arguing about what constitutes flex, moaning it was unfair, and/or looking to pick holes in the wording of the regs to justify a personal point of view.

[RZS10]

Hey, one can still compare to see if there was any change

But pretty much everything else was discussed multiple times to exhaustion, that's true.

[OO7]

During the Brazilian/Sao Paulo Grand Prix, there was a replay of the start from the rear facing T-cam on Verstappen's car. It showed his rear wing angle to one side quite notably off the line, as his car accelerated from stand still. I'd estimate the rear wing angling happen anywhere between 5 - 15 mph.