Flexiwings 2024

[AR3-GP]

You aren't allowed to design a mass damper (an obvious one). The Renault system was idealized, but IF a team wanted to reproduce the effects (in a reduced capacity), they would have had to get creative. It couldn't work as well as the Renault system, but "something" can be better than nothing.

Maybe the wobble of the rear wings can be tuned? It could depend on how it is mounted and the stiffness. It's either hindering you or it's tuned to benefit you. I think an F1 team would be smart about this.

What kind of damping properties did W15 front wing exhibit in Bus stop at Spa?

The wing stopped wobbling so isn't that proof that there is mechanism by which the oscillation energy is consumed (i.e damped)?

The goal of something that had any mass damping property would be to wobble out of phase with the chassis in order to counteract oscillations of the contact patch loads.

I think there's more here than I originally thought. I also dismissed the idea at first. Doesn't this sound like something that an F1 team chasing small margins would try and refine? Even the rear wings have a wobble. To truly model the car in the sim, it would make sense to include these parts of the dynamics. Once included, you would understand how to optimize the way the components should wobble to maximize performance.

[Vanja #66]

The wing stopped wobbling so isn't that proof that there is mechanism by which the oscillation energy is consumed (i.e damped)?

The goal of something that had any mass damping property would be to wobble out of phase with the chassis in order to counteract oscillations of the contact patch loads.

I think there's more here than I originally thought. I also dismissed the idea at first. Doesn't this sound like something that an F1 team chasing small margins would try and refine? Even the rear wings have a wobble. To truly model the car in the sim, it would make sense to include these parts of the dynamics. Once included, you would understand how to optimize the way the components should wobble to maximize performance.

A pressed/stretched and released spring will not wobble to infinity, it will come to a stop eventually, most often after a few dozen seconds. That doesn't make it a damper, it simply exhibits dissipation like any other object would.

Let me rephrase the question - what kind of performance-enhancing damping properties did W15 front wing exhibit in relation to the rest of the W15 chassis at Bus stop at Spa? I honestly didn't see any, it just wobbles like any other wobbling wing would and introduces unwanted oscillatory disturbance to the front axle.

You want to dampen oscillations of the chassis immediately, not introduce another order of oscillations on a cantilever (nose-wing assembly is a cantilever on the chassis bulkhead basically)

[ispano6]

The wing stopped wobbling so isn't that proof that there is mechanism by which the oscillation energy is consumed (i.e damped)?

The goal of something that had any mass damping property would be to wobble out of phase with the chassis in order to counteract oscillations of the contact patch loads.

I think there's more here than I originally thought. I also dismissed the idea at first. Doesn't this sound like something that an F1 team chasing small margins would try and refine? Even the rear wings have a wobble. To truly model the car in the sim, it would make sense to include these parts of the dynamics. Once included, you would understand how to optimize the way the components should wobble to maximize performance.

A pressed/stretched and released spring will not wobble to infinity, it will come to a stop eventually, most often after a few dozen seconds. That doesn't make it a damper, it simply exhibits dissipation like any other object would.

Let me rephrase the question - what kind of performance-enhancing damping properties did W15 front wing exhibit in relation to the rest of the W15 chassis at Bus stop at Spa? I honestly didn't see any, it just wobbles like any other wobbling wing would and introduces unwanted oscillatory disturbance to the front axle.

You want to dampen oscillations of the chassis immediately, not introduce another order of oscillations on a cantilever (nose-wing assembly is a cantilever on the chassis bulkhead basically)

In my view it's important that the first wing plane is detached from the nose such that the 2nd element is the "main plane". There are two certain consequences of this design. This being because the moment you hit a curb, the front wing leading edge angle will change, if attached at the very front of the nose, will lift the front like a surfboard or ship, but if not detached, the leading edge is ever so slightly less prone to the lift angle as the load on the leading edge and gap between the first two planes are allowed to compress with the leading edge able to help to keep the car pointing down while using the first major wobble as your counter-rebound balance and the subsequent oscillations to dissipate the force through the wing instead of the suspension. In order to facilitate this, you would need the aid of a spoon lip, and Mercedes having experimented quite a bit in this area I would argue is the pursuit of replacing the banned hydraulic suspension components with a passive/static/wobbly/deliberate form (since the suspensions are run so stiff now). The leading edge plane's shallowness/depth can also determine it's flex nature. Bringing in the rubbing-bracket towards the center-line of the chassis is effectively tuning the oscillation frequency. The 2nd element main-plane is the sturdiest obviously with the rest of the elements able to oscillate. The enhancement is of-course drive-ability and confidence inspiring performance to eek out hundreths/tenths riding curbs and bumps. The amount of flex allowed on the FW and the frequency is indicative of a "tuned" aspect relating to the orientation of the construction of the mass and the resulting dampening effect it has. Perfect example of a "tuned mass damper" just not one that is of the "conventional" or "coil or fluid actuated" that has been banned in regulations.

[Vanja #66]

In my view it's important that the first wing plane is detached from the nose such that the 2nd element is the "main plane". There are two certain consequences of this design. This being because the moment you hit a curb, the front wing leading edge angle will change, if attached at the very front of the nose, will lift the front like a surfboard or ship, but if not detached, the leading edge is ever so slightly less prone to the lift angle as the load on the leading edge and gap between the first two planes are allowed to compress with the leading edge able to help to keep the car pointing down while using the first major wobble as your counter-rebound balance and the subsequent oscillations to dissipate the force through the wing instead of the suspension. In order to facilitate this, you would need the aid of a spoon lip, and Mercedes having experimented quite a bit in this area I would argue is the pursuit of replacing the banned hydraulic suspension components with a passive/static/wobbly/deliberate form (since the suspensions are run so stiff now). The leading edge plane's shallowness/depth can also determine it's flex nature. Bringing in the rubbing-bracket towards the center-line of the chassis is effectively tuning the oscillation frequency. The 2nd element main-plane is the sturdiest obviously with the rest of the elements able to oscillate. The enhancement is of-course drive-ability and confidence inspiring performance to eek out hundreths/tenths riding curbs and bumps. The amount of flex allowed on the FW and the frequency is indicative of a "tuned" aspect relating to the orientation of the construction of the mass and the resulting dampening effect it has. Perfect example of a "tuned mass damper" just not one that is of the "conventional" or "coil or fluid actuated" that has been banned in regulations.

There is a fundamental difference between damping and dissipation. This is damping:





This is practically dissipation:



This is graphic representation of various damping properties. Ideally, you cover the entire lap with critical damping and nothing makes your car oscillate vertically (like that flapping W15 wing would), because this unloads your tyres and costs you traction and lap time.

[AR3-GP]

This is graphic representation of various damping properties. Ideally, you cover the entire lap with critical damping and nothing makes your car oscillate vertically (like that flapping W15 wing would), because this unloads your tyres and costs you traction and lap time.

https://xmdemo.wordpress.com/wp-content ... oscda8.gif

Should Mercedes make their wing stiffer?

[Vanja #66]

Should Mercedes make their wing stiffer?

That kind of question is kind of unnecessary, isn't it? The wing is obviously very light and flexible for aero balance reason and we can be certain those trump any other negatives of such a design. Otherwise, it wouldn't be designed like that to begin with

[Waz]

Should Mercedes make their wing stiffer?

That kind of question is kind of unnecessary, isn't it? The wing is obviously very light and flexible for aero balance reason and we can be certain those trump any other negatives of such a design. Otherwise, it wouldn't be designed like that to begin with

The low speed oscillations seem more as an undesirable by-product, that a team wouldn't be fully aware of the total extent until fitted to a car running on track.

Modelling something like this must be nearly impossible. How do you simulate curb strikes and then the resultant effect on the material? Especially if most of the desired flex is caused by the manufacturing process.

Edit: would a stiffer wing improve low speed performance?

[Vanja #66]

Modelling something like this must be nearly impossible. How do you simulate curb strikes and then the resultant effect on the material? Especially if most of the desired flex is caused by the manufacturing process.

Edit: would a stiffer wing improve low speed performance?

This is a dynamic, multi-body FEM simulation. You can simulate kerb strike with any additional boundary condition, but I guess it would be hard to accurately model everything to exact same boundary conditions as they are on race track. You don't really need to, if you are doing dynamic stress calculations to check if there is a case where this type of elastic wing might be in danger of breaking due to resonance or other phenomena.

In Mercedes' case, I don't think this wing flapping in very specific conditions in Spa is an issue. It can't generate a very high acceleration amplitude, oscillation dissipates eventually and the whole thing is not that heavy. Ballast is typically in the nose tip and the nose itself is practically immovable, so that extra weight is fixed the whole time.

[Waz]

That's incredible, thank you.

Edit: Found an article describing just what FEM and multi body modelling is, for the non-engineers interested in this topic.

https://new.abb.com/news/detail/80786/m ... simulation

[ispano6]

The initial behavior exhibited by the wing isn't caused by aero forces, it is the force of hitting curb. The resulting oscillation is a combination of the reactionary force, the damping properties and frequency of dissipation amount may be affected by aero forces acting upon it. The location of the parts that oscillate the most are in the ideal location of the mass damper. Engineers have gotten quite clever in utilizing structures such as flexiwings for secondary and tertiary purposes and while no one sees this as a mass damper used by Renault, the importance of such a system cannot be understated, especially with stiff chassis vehicles( like Mini 4WD and RC platforms where they make a considerable difference). I've actually simulated this with replacing carbon with lexan sheet made front wing stays and the ability to ride curbs changes immensely.

While it's not a flexi-wing example, here's a good example of the difference it makes.

[SiLo]

I'd say it's much more just dissipation than any real kind of damping, especially given how long the wing continues to bounce.

[Vanja #66]

The location of the parts that oscillate the most are in the ideal location of the mass damper.

This cannot be further from the truth

[ispano6]

The location of the parts that oscillate the most are in the ideal location of the mass damper.

This cannot be further from the truth

Please offer a rational explanation then if you know precisely the correct location where such a system should go and convince me.

I too wasn't specific so I wonder how you can say what I'm referring to as far from the truth. Which part do you think I'm referring to as the most ideal location? Flap or plane? How far from the center line?

Also, this is with regard to the current chassis regulation and where teams CAN exploit parts and materials for extracting the purposes of said mass-damper.

The reasons are the same as back in 2005:

The Enstone-based team had found the rules introduced for 2005 required it to run an excessive amount of front spring stiffness to keep the front wing as close as possible to the ground. This was the sort of mechanical trade-off that teams typically make to try to find aerodynamic performance.

The possible loopholes that are being exploited, but how with these regulations"

FIA introduced technical directive to combat flex during 2023 season

Last year, the governing body introduced TD018 which came into effect at the Singapore Grand Prix but had been outlined around the time of the Dutch Grand Prix weekend earlier that season. No team fell foul of any rule-breaking, nor were ever singled out by the FIA, but the governing body sought to tighten up an area it felt was being exploited by the teams.

With F1 teams always doing what’s possible in the grey areas of the rules when it comes to bodywork flexibility, the suspicion was that some had found ways to use variability in the flexibility of a part or in the movement between interconnected parts.

“What we don’t want to see is that, at the joint of, let’s say, a rear beam wing to an endplate that it’s decoupled in any way such that it can rotate about a pivot or it can move laterally or up and down,” said then-FIA single-seater director Tim Goss.

“So we’re saying that you can’t have very localised motion of one component relative to another. The assembly can move as a whole body but we don’t expect to see parts of it being able to translate relative to others.”

The exact nature of what the teams may be doing this year hasn’t been addressed in detail, but a report in Germany’s Auto Motor und Sport claims Red Bull is leading the pushback against the level of flexibility seen at McLaren, Ferrari, and Mercedes.

“Christian Horner told me that the FIA are ‘playing a bit blind’ and claims that everything is fine but to be honest all the front wings pass the technical inspection so it is fine/legal,” reporter Michael Schmidt wrote.

“What happens is that the front wings bend in a specific way, differently at every team, for some outwards, for some the flaps turn backward. The aim is for the front wing to lose downforce at high speeds.”
What do the F1 technical regulations permit?

The technical regulations regarding front wing flexibility are laid out in Article 3.15.4, which explains how front wing flexibility is scrutineered – some tolerance has to be built in as every material will flex to a certain degree.

Loads of 1000 newtons (about 100 kilograms static) is applied along three different points of the wing, in a downward direction, using a 50-millimetre diameter ram. Fitted to a rectangular ram supplied by the team, the amount of deflection is measured relative to the survival cell and along the loading axis.

“When the load is applied symmetrically to both sides of the car, the vertical deflection must be no more than 15mm,” state the rules.

“When the load is applied to only one side of the car, the vertical deflection must be no more than 20mm.

“No part of the trailing edge of any front wing flap is permitted to deflect more than 5mm when a 60-newton force is applied.”

https://www.planetf1.com/news/f1-flexib ... -explained

Lots of the use of the word "load". Bolded text of wings bending backward describe primary purpose of flexiwing.
The forces we see in the behavior of the wing at LOW speed does not exhibit behavior due to LOAD. Load would be pressing DOWN on the wing. You can design your wing to be stiff in one direction and flexible in another. Then the other loop hole is the amount of movement that is being exhibited and allowed of a trailing edge being no more than 20mm. How much movement do we see in the Merc FW oscillations? Precisely within 20mm at all points of all trailing edges? (what I'm trying to get at is the loophole that you can exceed that movement if the movement isn't due to aerodynamic load)

[Vanja #66]

The location of the parts that oscillate the most are in the ideal location of the mass damper.

This cannot be further from the truth

Please offer a rational explanation then if you know precisely the correct location where such a system should go and convince me.

You don't place a mass damper outside of symmetry plane and you don't put it on a cantilever. You make a single unit and not on two separate flexible cantilevers that can and will osciallste at different frequencies. Ideal location for a mass damper targeting front axle is in the intersection of the symmetry plane and front axle plane. In practice, it will sit in the nose and as close as possible to the bulkhead, you know - like Renault actually made it

[AR3-GP]

You don't place a mass damper outside of symmetry plane and you don't put it on a cantilever. You make a single unit and not on two separate flexible cantilevers that can and will osciallste at different frequencies. Ideal location for a mass damper targeting front axle is in the intersection of the symmetry plane and front axle plane. In practice, it will sit in the nose and as close as possible to the bulkhead, you know - like Renault actually made it

Mass dampers are not legal. That is the point of a non-traditional implementation.