TD039

[Zynerji]

In which case the input force is delivered from the ice skate, correct?

And the bib possibly

Wouldn't the roll across the axle(s) alone cause the edges of the plank to come into contact with the ground?

Not if the suspension was doing its job properly.

[vorticism]

The ice skate bends the entire floor keeping it and the plank relatively level to the track while the chassis rolls normally. Hence why only the outer edges of the plank are worn in the RB18 plank photo.

Diagram:

[chrisc90]

Are the new regs really going to stop though though? Yes we are going to have additional tests on the plank, and 2023 will see a 15mm raised floor edge, but is it going to stop floors from cantilevering over and resting on the 'skate'? 15mm isnt exactly a huge amount if you think of roll on a car given its pivot points along the central plane. 15mm could be easily achieved with a couple less lb's of suspension stiffness allowing the car to roll over more, and still utilise the 'skate'. Only concern is your floor at the other side is higher up

I could be barking up the wrong tree, but if thats what its designed to alleviate - then its easily got round

[Alexf1]

Are the new regs really going to stop though though? Yes we are going to have additional tests on the plank, and 2023 will see a 15mm raised floor edge, but is it going to stop floors from cantilevering over and resting on the 'skate'? 15mm isnt exactly a huge amount if you think of roll on a car given its pivot points along the central plane. 15mm could be easily achieved with a couple less lb's of suspension stiffness allowing the car to roll over more, and still utilise the 'skate'. Only concern is your floor at the other side is higher up

I could be barking up the wrong tree, but if thats what its designed to alleviate - then its easily got round

What would be interesting to know is what the current min floor edge height is in the regulations. If we compare an early season photo of the team running the closest to the ground (they will probably be near or on the limit) to other teams current height and see 15 mm difference we can presume there are teams who don't have to increase their current height. My take is that some teams won't have to increase, especially if you run a tiny bit of rake with softer rear suspension. But I don't know what the min height is in the 2022 regulations

[henry]

The ice skate bends the entire floor keeping it and the plank relatively level to the track while the chassis rolls normally. Hence why only the outer edges of the plank are worn in the RB18 plank photo.

Diagram:

https://i.imgur.com/hCPpNx9.png

Thanks for illustrating what I wrote about.

A couple of other points.

As well as this “active” means of tilting the plank it is likely they also use “passively localised twisting of the plank/floor. Both would reduce the force of the plank edge on the ground during roll and as well as bringing the funnel closer to the ground there will be a slight increase in load on the tyres and hence cornering force.

Twisting the plank in this way would allow lower roll stiffness in the suspension potentially increasing traction. A benefit in low/medium speed corners as well as the faster ones.

I think the TD only deals with the “passive” mechanism, local flexing. We’ll see how much effect that has.

[chrisc90]

I know this might not be strictly td039 to the letter…. But…

How are current floors and planks mounted? Would it be possible to solidly bolt the plank to the tub, but mount the floor on some stiffer rubber/poly bushings which would allow the floor to move independently to the plank which won’t move.
Could be similar setup to what they have now in terms of how they mount

[vorticism]

The ice skate bends the entire floor keeping it and the plank relatively level to the track while the chassis rolls normally. Hence why only the outer edges of the plank are worn in the RB18 plank photo.

Diagram:

https://i.imgur.com/hCPpNx9.png

Thanks for illustrating what I wrote about.

A couple of other points.

As well as this “active” means of tilting the plank it is likely they also use “passively localised twisting of the plank/floor. Both would reduce the force of the plank edge on the ground during roll and as well as bringing the funnel closer to the ground there will be a slight increase in load on the tyres and hence cornering force.

Twisting the plank in this way would allow lower roll stiffness in the suspension potentially increasing traction. A benefit in low/medium speed corners as well as the faster ones.

I think the TD only deals with the “passive” mechanism, local flexing. We’ll see how much effect that has.

You're welcome, you made a good point about axial deflection. My only question is, if this is being done, how much of a compromise is there to CoG considering some gap for travel might need to exist between the crankcase and the plank. To prevent this behavior, the plank test would need to include a pulling of the plank, or pushing is side to side. Currently it's all compressive--they simply push the car up with rams on and through the plank.

[henry]

Diagram:

https://i.imgur.com/hCPpNx9.png

Thanks for illustrating what I wrote about.

A couple of other points.

As well as this “active” means of tilting the plank it is likely they also use “passively localised twisting of the plank/floor. Both would reduce the force of the plank edge on the ground during roll and as well as bringing the funnel closer to the ground there will be a slight increase in load on the tyres and hence cornering force.

Twisting the plank in this way would allow lower roll stiffness in the suspension potentially increasing traction. A benefit in low/medium speed corners as well as the faster ones.

I think the TD only deals with the “passive” mechanism, local flexing. We’ll see how much effect that has.

You're welcome, you made a good point about axial deflection. My only question is, if this is being done, how much of a compromise is there to CoG considering some gap for travel might need to exist between the crankcase and the plank. To prevent this behavior, the plank test would need to include a pulling of the plank, or pushing is side to side. Currently it's all compressive--they simply push the car up with rams on and through the plank.

They may already isolate the crankcase from the floor for reliability. In general COG loses out to aero most of the time.

I think it might be difficult to devise a test for twist, since they need to support the car at the same time. Loading on the plank edge might do the trick, measuring the difference in deflection at the edge and the centre.

[SiLo]

Just so I can keep up, are we talking about the plank twisting along its axis from front to rear? So the leading edge of the plank would stay parallel to the track, but as you move down the plank to the rear of the car, it twists and lifts the inside edge?

[Zynerji]

Just so I can keep up, are we talking about the plank twisting along its axis from front to rear? So the leading edge of the plank would stay parallel to the track, but as you move down the plank to the rear of the car, it twists and lifts the inside edge?

I think so. My wife called it a pilates type maneuver (she knew the proper name) when I explained it to her.

[TimW]

I think you guys as on the wrong track here. As several have noted the RB18 shows a very high roll stiffness, nothing to suggest that they use roll+ twist to their advantage(if their would be any advantage in doing so). The floor edge stiffness will be pretty independent of the bathtub section's stiffness anyway, and there is am independent stiffness test for that.

The supposed 6mm of deflection most likely would be in the bathtub center. If you look at the wear pattern you see less wear there.

That the bathtub center is more flexible is a natural result of the shape. Making this section have a similar stiffness can only be achieved by connecting it to the chassis here. But since there is no benefit in doing that, on the contrary, I understand they 'neglected' to do so.
However you still have the 'hard spots', the test locations fore and aft, where you see most wear. Since these also have to pass over any road bump you encounter, the benefit of the soft central section won't be huge.

The real benefit I think they are getting is increased wear limits. The way they mount the skid blocks(and split them in RB's case) will make them wear asymmetrically. Since they only check the highest point of the skid blocks, asymmetric wear will increase your wear limit. Of course you need the plank to accommodate as well.
With the directive this will the effectively decrease their wear limit. So the will have to increase ride height to have less bottoming, which will cost some lap time.

[henry]

Just so I can keep up, are we talking about the plank twisting along its axis from front to rear? So the leading edge of the plank would stay parallel to the track, but as you move down the plank to the rear of the car, it twists and lifts the inside edge?

It’s probably a combination of twisting along the x axis and bending across the plank in a y plane. At least for the Red Bull the plank is maintained flat to the ground even though the car is in roll. So twisting the front of the plank with the bib and the rear with the skates is a possibility.

[GrizzleBoy]

Is one big advantage of skates that they can actually be a bump stop for the floor edge so that the floor never actually flexes and completely seals down to the ground?

That would mean the floor will only ever reach a controllable level of peak downforce and not porpoise.

Meaning you don't need to have a slimmer rear wing to reduce the amount the car is pushed down to limit the hard seal of the floor at high speed.

Meaning you can have good grip and traction at lower speeds too.

[Big Tea]

Is one big advantage of skates that they can actually be a bump stop for the floor edge so that the floor never actually flexes and completely seals down to the ground?

That would mean the floor will only ever reach a controllable level of peak downforce and not porpoise.

Meaning you don't need to have a slimmer rear wing to reduce the amount the car is pushed down to limit the hard seal of the floor at high speed.

Meaning you can have good grip and traction at lower speeds too.

Would it be feasible to 'mandate' such skates? Possibly front and rear corners of the floor outer edges?
This could then ensure the gap is never less then the (approved) size of the skate.
It could be higher if needed, but once the skate is on the track it can go no lower and the plank ensures the middle does not ride.

[vorticism]

Only one photo, but presence of rake angle is shown at plank-ground interface: