Mclaren Mercedes MP4-25

[Just_a_fan]

The end plates DO have a structural role. . Without those, the ends of the wing would droop under air pressure, which can be quite severe. I doubt that the plates are hollow, as foam would be used so as to provide the required shape and rigidity. I still see it as a poor lay-up, or bonding problem, which shouldn't really be happening.

I disagree. The wing's profiles are quite deep for their span so they will be inherently stiff. Deflection under aero load at speed will be minimal unless designed for. The rear wing is not at all like the front wing in this regard.

As for hollow end plates - why not. If the two skins are formed independently and then glued together they could be made as hollow sections quite easily. This should be lighter than a cored piece too.

The delamination is more likely to happen with a hollow section anyway as it's only held together around its edge rather than across the whole piece. A small lay up error would then be more likely to fail in this sort of accident.

[gerishnikov]

firstly I just want to say hi to everyone as I am a long time lurker

from the pictures of the rear wing ep It looks to be constructed in two halfs with a nomex honeycomb core (or possibly a roahcell core), i would imagine that the two halfs are layed up then the core fitted and finally the 2 piece mould being closed togeter to join the component. Obviously i cant comment as i have never mnufactured mclarens rear wing ep's but i would imagine thats their process

[Pup]

a) the end plates are most certainly structural, unless you believe McLaren are magically suspending the upper element in the air.

b) the bit that peeled off isn't necessarily structural, as it obviously ends short of the wing elements - and my guess is that it isn't, judging from the way it came off. I don't think something that had been cured as one piece would fail in that way. My guess is that it's a very thin piece that's glued on afterwards and only exists for aero purposes.

[PlatinumZealot]

Don't forget that the rear wing end plates are just aero parts now with little, if any, structural role. The rear wing is centrally supported these days so even if the end plate failed totallt, the only thing likely to happen is that the rear end aero becomes less effective.

I'd have been more worried if the central pillar had shown some damage from the impact, however.

The end plates DO have a structural role. . Without those, the ends of the wing would droop under air pressure, which can be quite severe. I doubt that the plates are hollow, as foam would be used so as to provide the required shape and rigidity. I still see it as a poor lay-up, or bonding problem, which shouldn't really be happening.
Another peculiarity is the way that the outer layer is bent. CF is quite rigid and brittle, and if not formed to that shape, it should have shattered. A small amount of flexibility is available, but hardly a sharp s-bend.

THe glue is good in sheer. As we know. That failure looks to be from a twist that has both shear and tension in it. That is why the whole layer just popped off. It's interesting that JB's end plate tore the same way in Monza.

The structual contribution of the end-plates is a mystery to me. I know that the loads always travel through the stiffest memeber. and the central pillar looks to be several times stiffer than the end plate. Not to mention the many times we see guys driving around with no endplates; just the central section holding up the wing. I would say the end plate was primarily designed for aero and not strength. Because we see that the lengh of the end plate is not critically designed. that is it is not wider or narrower on high/low down-force tracks.

[mep]

As for hollow end plates - why not. If the two skins are formed independently and then glued together they could be made as hollow sections quite easily. This should be lighter than a cored piece too.

Those endplates are just around 3-4mm thick. It doesn’t make much sense to make them hollow or to put a core into them.

I wonder what even caused them to fail. The rear suspensions seems to be still ok so I wonder if the rear tire was able to hit them. The crash doesn't look like there was a significant impact on the rear and those weak endplates already broke.
It's nothing compared to the tank like Ferrari Alonso had in Spa. Even the massive impact of Barrichelo could not destroy it.

[scarbs]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

[Giblet]

I wonder what even caused them to fail. The rear suspensions seems to be still ok so I wonder if the rear tire was able to hit them. The crash doesn't look like there was a significant impact on the rear and those weak endplates already broke.
It's nothing compared to the tank like Ferrari Alonso had in Spa. Even the massive impact of Barrichelo could not destroy it.

If by fine, you mean broken, then sure. Look at the pics. The rear arms are mostly shattered, the endplate bottom was hit with the wheel it looks like, while the wing itself being held the top in place. The 'dots' under the rear wing profile look as though they failed from a load completely out of scope for a wing endplate.

The simple fact that Macca cars aren't delaminating all over the place should be enough evidence that this is out of the ordinary, and scarbs has confirmed my guess. Hollow and held together at the edges.

[mx_tifoso]

Recent EBD related posts were moved into the 'RBR Engine mapping thread.

[aral]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

If there was a foam or honeycome interior, there would be evidenc of this in the photos. If a filling is used, the CF has to bond to it, so the remnants would be clearly visible. This still, to me, appears to be simple delamination.

[aral]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

If there was a foam or honeycome interior, there would be evidenc of this in the photos. If a filling is used, the CF has to bond to it, so the remnants would be clearly visible. This still, to me, appears to be simple delamination.

[aral]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

If there was a foam or honeycome interior, there would be evidenc of this in the photos. If a filling is used, the CF has to bond to it, so the remnants would be clearly visible. This still, to me, appears to be simple delamination.

[feynman]

Of course the endplates are 'hollow'.

Actually laminated.

You don't build that size of flat plane structure out of solid carbon fibre, you use honeycomb or foamcore for lightness, and the process of laying up in laminate layers between carbon-fibre to maintain structural rigidity.

What exactly do we make of armchair internet experts telling McLaren composite engineers (McLaren, the guys that pretty much brought carbon to F1) how to do their job properly, when they apparently weren't even aware of this basic technique.

[ell66]

did anybody else hear what ted kravitz had to say about a new rear wing aimed at stalling BOTH rear wing elements for korea?

[Giblet]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

If there was a foam or honeycome interior, there would be evidenc of this in the photos. If a filling is used, the CF has to bond to it, so the remnants would be clearly visible. This still, to me, appears to be simple delamination *from an impact*.

There I fixed that for you.

[scarbs]

F1 endplates are 'hollow', they differ in cross section and hence are formed of two skins over a honeycomb and rohacell core.

If there was a foam or honeycome interior, there would be evidenc of this in the photos. If a filling is used, the CF has to bond to it, so the remnants would be clearly visible. This still, to me, appears to be simple delamination.

No, their hollow with rohacell (the white stuff in the pics) or honeycomb between the skins.