i was shocked seeing him walk around the paddock like normal towards the end of the race. Thank god for all the safety measures that saved Zhou's life.
yeah sure but that's to be assumed. in a similar time period rally cars have improved beyond this to a point where you can just send a WRC car into a ditch at 100 mph and the rollcage will keep you safe. formula 1 cars of course cannot have such a huge cage around them but my point is I don't think that crash was so bad that you couldn't survive it in a top spec fully modern race car of any sort
Let's appreciate that even though the result of this accident is that the driver is able to compete less than a week later, we are still pushing for safer cars.
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@@alunesh12345 this was all mechanical engineering masterclass in a league of its own, don't even attempt to pull that Jesus bullshit into this matter because he doesn't exist and it is all lies.
safety has to first, second, third, ... and last. anything that even has the potential to jeopardise any safety should be top priority for all regulators and officials. if this blade style roll hoop has any sort of weakness, then raise the standards. safety improvements should be as maximalist as possible. i don't ever want to hear news of an F1 driver getting killed in a race ever again... not even any serious injuries. on that note, sausage kerbs need to be eliminated.
Wouldn't have saved 4 out of 20 drivers in the current grid, though. Taller drivers heads protrude over the halo line and they wouldn't be able to duck when inverted, bounching violently and HANS device restricts forward movement. And a few more drivers would have their helmets touching the tarmac as well. Luckily Zhou happens to be one of the more average sized drivers.
@Goat Exactly, that's why the roll hoop is the principal roll structure. But it snapped off and halo has the secondary roll stucture role. But those taller drivers would have been severely injured in an identical scenario.
@@kekkonenprkl Is there a specific height for the halo? As a primary safety device, I would think that the regulation would require a “minimum height above helmet” Sounds as though you know more than I do since I didn’t even think about driver height - just wondering
Both it and the halo are not part of the monocoque. They can’t be - they’re made of titanium while the monocoque is a carbon honeycomb composite. Both have to be attached to the monocoque with either glue or fasteners.
Unfortunately, a carbon fiber roll hoop would just get worn away really quickly. Carbon fiber is very strong but hardly abrasion resistant enough and would still deal with the delamination (layers coming apart) issues
I find it incredible that just 4 years after the highly contentious introduction of the halo, the number of lives saved and injuries prevented across open wheel categories is staggering. Zhou can consider himself one of the lives saved.
If i remember right it was: - Leclerc - Zhou - Hamilton - Grojean did i miss anyone (counting only F1 here but in F2 and F3 there were also other lives saved)
@@rnichol22 Verstappens car slipped over the hoop into the halo, without the halo it's quite likely that Verstappens rear right tire would have landed on Hamiltons head, which probably would have caused some injuries if not fatal ones.
@windrose5988 it is not necessarily about the rotation of the rear tires but rather the weight. Most of the cars weight would have dropped down on hamiltons head which quite likely would have broken his neck or similar injuries
You're spot on about "welding glue" used in F1 being so strong, it's actually stronger than welding and is the same as used in the aeronautics industry and was developed to replace welding or riveting in low drag aircraft such as stealth planes so has to be able to withstand pressure at mach III plus.
I don't know what glue you've worked with, I work in the aerospace industry on spacecraft and glue (like EA9394) is pretty weak, certainly when compared to welding. As with all fastening methods it's obviously more than just the tensile strength of the component, and that's where glue is nice since you can put a large bond line on something. But with the same area of welding and bonding, I'm not aware of any glue that is stronger than a 70ksi weld.
@@TheSnivilous scotchweld is pretty strong🤷♂️ theyre probably talking about the epoxies used for composites when you do a wet lay up, that shits really strong
With how carbon works, it's likely that the initial vertical drop on the roll hoop caused the initial delamination of the carbon fibre layers in the monocoque, which then led to the carbon fibre being weakened and made it easy to tear off. Kinda scary looking at it, but it's good to see him walking and alive.
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Great video. It looks like they need to anchor it in new ways. Maybe a combination of screws and bonding lower down in the chassis. They also need to look at the fencing. The scariest part of the accident was the gap that the car got stuck in. There’s no way Zhou could have survived a fire like Romans and the car was fully loaded with fuel.
I think Grosjean's crash saved Zhou. FIA apparently learned from Grosjean's incident and implemented new fuel tank design requirements for this year's new cars to reduce the chance of the fuel tank being ripped apart and catching fire.
I actually think the gap is less of an issue than the surface of the runoff area beneath the gravel. There's a ledge before the tyre wall which is what launched the car.
Either no gap at all, with escape/entry windows/gaps in the fence for marshals and/or drivers to pass through. Or a gap wide enough, so a car can't get stuck sideways in the narrow trench like it did.
@@kekkonenprkl apparently they need a gap as a buffer zone for the barriers to move inwards in case of a more common front collision. They never expected a car to flip over the barriers. I think a wider gap would work if space allows.
@@willw.3366 Didn't realize the tyre barrier is required to be able to move inward, as the tyres are stacked against a low, probably a meter high steel barrier. But it makes sense. So i assume that steel barrier is designed to deform at a certain rate, to make the tyre wall stiff enough for the initial impact but to allow them to move and release energy right after? I agree, a bigger "trench" would be the way to go then.
The thing I absolutely love about mechanical engineering is just how much you can learn when designs fail. I'm very happy Zhou walked away from this incident and because this critical safety part failed, it will be redesigned in hopes that it never does again.
The safety part didn't fail, the carbon fiber it was attached to failed. In order to prevent this again, it will take a drastic change in regulations and design. It would take something more akin to a "roll cage" around the cockpit to prevent such an event; something all the way to the floor of the chassis. The carbon fiber will always be the weakest link.
@@Parker-- Ah remember when cars started getting bigger and heavier and everyone was on board with it because of "safety", it is so ironic that those bigger and heavier cars behave in dangerous ways during cashes. When cars where lighter roll structures didn't crumble so easily and cars just flipped again instead of sliding upside down.
@@Ale-nv2bo There's always give and take and all the rules regarding everything else are arbitrary to begin with. If they want to make a legitimate change so that the car is safer in this situation again it will take a drastic change. Of course, the question is do they actually want to make such a dramatic change for safety? Who knows. They could just as easily shrink the cars back down, still add a roll cage and keep the speed by changing engine specs and a billion other arbitrary rules if they wanted to. It's a matter of if they actually want to.
@@Ale-nv2bo Surely you would rather be sliding in a car with a feature to stop your head getting hit than being in a car that’s flipping with no feature
It was shocking seeing Zhou’s car being tossed around and dragged on the track and then stopping at the tire barrier. I watched it live on F1TV, and I couldn’t believe it when the accident happened. I’m glad that Zhou came out ok from this accident. It could’ve been so much worse. Thank you for the excellent breakdown, Scott!
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When I was doing them there was the combined static test and there was a reverse theoretical test that you passed by proving your calculations in FEA. The latter was very often, er, well, extra material is extra weight and up there it heavily effects your CoG, so yeah, the reverse test calcs were perhaps wishful thinking. Also bears mentioning that the hoop passes ONLY this combined test, swap the values around, change the values, worn't pass. Remember the old side crash tubes? Literal tubes at 90deg to X? Literally only worked along their axis, hit the barriers slightly oblique and they were useless. The cars are designed within the rules with no consideration to driver safety, dirt truth. The rules need to consider this, always. However, no-one will stand up in the TDs meetings and say "we know our car is unsafe in situation X, please change the rules".
Thanks Scarbs! I've been thinking exactly the same thing, the FIA does test these roll hoops thoroughly but the bonding with the chassis is what most likely failed. The FIA should look into it, but as the tests stand now, the roll hoop met specifications.
Nah, it's much more likely that the carbon fiber layer it was bonded too sheered off. As mentioned, carbon fiber is not resistant to forces along the layers. This is why Lamborghini and their partners created Forged Carbon Fiber that has similar strength in all directions (though I believe less strength than traditional carbon fiber has against the weave).
@@kalasmournrex1470 You can clearly see leftover adhesive from photos. If it was only the carbon fiber there would be none because the roll hoop would have ripped the whole layer off
A great video again from Driver61. What I have learned from my co-workers ( one has done a Ph.D. in how to repair metal fractures of the airplane with glued composite plates) is that bonding is a much better way to connect parts than glue and bolted connections, less stress, and no weak points. I do a lot of fea calculations for rollover structures with implicit and explicit code, at this point for big machines, for example, the vertical load can be 100 tonnes. I do prefer explicit code because it allows progressive damage model to steel and weld structures and their alloys, to design lighter structures than implicit code.
yeah only problem with the glued composites is that for the calculations it is harder to define how the loads gets turned over. As for bolted/riveted (bolts are rarely used) connections you can to that way easier. In the c ase here i would suggest hat the adhesion between comb and top layer of the carbon failed. Therefore a bolted connections would improve that. because then the load would be applied to fully use the strength of thestructure. It also would help becuase such impacts can cause delamination which then weakens the carbon
I was wondering and if you could answer wonderful, and if not, maybe you could ask your friends: Could it be that the initial vertical impact damaged the carbon composite debilitating the bond between the top layers and the rest of the monocoque? Then, the sliding after could have caused the debilitated structure to detach? Could this happen to an up to spec part or maybe it suffered from defects during manufacture? It is my understanding that small imperfections in composites are both easy to appear during manufacture and hard to detect.
@@andresmartinezramos7513 I comes down how its all layered up. I dont know if they use a core for example or ift its just layers of CFRP. If its done with a core im sure the weak point is between core and the first layer of the net.
Is it possible that the “blade” style resulted in greater shear stress by digging into the track? A more rounded hoop would have perhaps been subject to lower sideways force as the car slid across the surface.
That tracks, I suspect we may see a ban on the blade style roll hoop, but I suppose we'll have to wait for the official investigation to bring all the facts and findings and a recommendation.
Or if it's the carbon that failed... maybe the whole titanium structure of the roll hoop should have... "tendrils" as it were, reaching out deep into different parts of the monocoque, rather than just being a small flat surface stuck to it.
@@PiousMoltar Even a few simple bolted connections in addition with the usual adhesive would prevent the top most layer of the carbon structure being subjected to all of the stress and tear away. The adhesive is strong enough, but the strength is limited to the layer strength it's directly bonded to. A few bolts would relieve some of that stress to a thicker area/volume of the structure. But they haven't done that because they aren't required to, as long as they pass the tests, they will use a method that saves most weight. But it wouldn't add much weight to the car if it became mandatory to add some bolted connections there, especially if a more exotic alloy would be used. Not for the current season though, can't really require them to update their monocoques with the current budgets until next year.
@@kekkonenprkl yeah and a plate on the other side to bolt into, just the bolts would not add that much strength because they would rip right through the carbon, but a larger brace or plate would require every carbon strand to snap, as well there should be carbon string layer in a sort of U shape imbedded into the carbon around the holes so that the bolts can’t slide and rip through the carbon, also keeping the adhesive
agreed, looks from this that the flat surface the roll hoop is bonded to has layer lines only on a single xy plane... an improvement could just be to bond to surfaces on the xz and yz planes as well, at least that way if one fails there are 2 other planes of layer lines to hold it.... i am not a composite expert, but it makes sense in my head!
Thanks for putting that together, was wondering what happened to the roll hoop there. Was so surprised to see only the halo keeping his head off the ground.
Hurts to think of what could've happened without the halo - the back of the car would've still been some protection as the front tips up, but his helmet would've been dragging for sure and who knows what injuries or worse could've happened.
The picture seems to show left over adhesive (those reddish spots that are left behind), so I'm not so sure that it was the carbon fiber alone, but certainly some of the adhesive clearly failed too.
I'm actually beginning to wonder if there was improper surface preparation on the monocoque: large regions of the adhesive were removed in their entirety which could suggest it had failed to properly bond to the carbon fibre.
@@jameshogge yet more to suggest a return to how it was done for last 50+ years without many issues. Even if the “new is better” brigade still want to glue the roll hoop on, why not use bolts too?
@@testpilotian3188 the glueing method spreads the load evenly, while the bolts method apply very strong pressure points right where the bolts are located, and also weaken the carbon fibre itself since you need to drill holes in it. I do not see a better solution other than increasing the amount of carbon surface woven into the roll hoop
@@Shiinamusiclyricssubs You would want to go the other way: carbon integrated into the roll hoop would break (its too stiff, you need something compliant to absorb energy) at the first deformation leaving just the titanium.
As a design engineer who has worked in aerospace composite design I have the following comments. Firstly this component took loads that were not envisaged st the concept stage. Secondly, while bonding is excellent,I think thos should be attached to the structure underneath better. Increased load paths and mechanical as well as bonded attachments.
Im surprised the Roll Hoop is not a more integrated part on the car. Instead of it being built into the monocoque, its just placed on top....not surprised it failed the way it did.
Carbon fiber would be a poor material to build a roll hoop out of. There are reasons they are made from titanium. And with that you have to connect the materials in some way. And again, I can't remember the last time we saw a roll hoop detach like that.
It SHOULD be surprising. With hindsight, it may seem obvious but the tests place very large loads on the region and provide a lot of evidence to suggest it is OK. My bets are actually on a manufacturing defect at this point. Improper preparation of the monocoque before bonding the roll hoop to it.
It really can't be made to be more apart of the car other than to have some spikes that go into the monocoque and are also glued in along with the other glue
I had imagined the roll hoop to be an integral part of the chassis and not just stuck on, this illustrates the teams are putting weight and performance before driver safety.
1:36- I hated the idea of the halo when it came out but, seeing this perfectly timed pic proved me wrong again. I don’t think Zhou would be alive or at the very least be able to walk if it hadn’t been for the halo. That said, maybe over the past few years the drivers have become a little too cavalier due to the cars being all but death proof at this point.
The cars aren't "death proof." That's the kind of ignorance and complacency that'll get drivers killed. Even if you think you've planned for every eventuality, there are still going to be things that you likely haven't accounted for. Murphy's Law: anything that can go wrong will go wrong.
@@wunkskorks2623 You said, "all but," meaning that you think they're nearly "death proof." That just simply isn't the case, which is why I pointed out the flaws in that thinking.
Huge congratulations for this video and your analysis: it was very interesting, really detailed and technically flawless. Thank you so much for helping us in better understand these techical topics.
I think that the design needs to be updated to have the actual roll-hoop extend much more below the current 'bonding' area ...The potential for such awesome and variable dynamic loads/stresses cannot all be accounted for ...and now that the authorities see that there is actually a failure point still present(bonding intersection in this case), they can do some updates. Extend the Roll-hoop 2, 3 or even 4 times lower into the Tub superstructure(even bonding it with the Tub structure at several points on different planes maybe?) ...I'm just so happy that Zhou was able to survive this one!
thought they were designed to deflect lose tires, not roll over protection because like you said, low center of gravity makes overturns very rare ...the monocock intake handles rollovers
I find it very odd that they are allowed a blade style hoop, or even a two-leg design. Zhou's crash showed one of the biggest issues with lab testing: the real world is much crazier. As it spun upside down, it essentially wiggled the blade and seemed to have broken the carbon. A four leg design most likely would've lasted a lot longer, as it can disperse the load across a much larger area. It is also surprising it is just bonded on top, instead of being made an integral part. The entire monocoque is handmade, so integrating it would be possible. Given how important it is, it would be a good way of retaining the hoop in an upside down slide.
Doesn't seem like rocket science does it. I agree, a 4 leg design seems like a no brainer. As for the testing.. Why they used a static load test for a part destined to experience impact, is a real head scratcher.
@@M3rVsT4H Same reason helmet makers test their helmets in static form: it would never pass a dynamic test. The latest standard in MotoGP is the first to do dynamic and random testing, coming closest to a real world scenario.
@@Yvolve Now helmets I get. Wherever big profits are to be found, you will find shortcuts. But nobody gains from this... Other than just not wanting to crash test such an expensive monocoque.. I can't think of a reason why you wouldn't just test thoroughly. but oh well, I guess that's why they get paid the big bux.
That wouldnt hae made a difference. the mono is essentially a composite of carbon fibre and a comb between the layers. What happened here is that it sheared at the comb so the top side was gone but bottom side was intact. Thats the biggest problem if oyu glue it. You get the weakest point between the layers and the comb. if you bolt the roll hoop the differs. not the bolt is hold underneath the whole therefore it is way more resitant to shearing.
Hot take: The roll hoop should be a standardized part built using tried and true methods. There is no need to allow the constructors to design their own. Its a matter of driver safety and if everyone has the same part the competition won't be affected.
I used to build yachts and bonding parts to parts was on the increase to save 'through bolting'. However, we had delamination problems too. If a part failed, the naval architects would put plate (ply or metal plate) beneath for strength. Then ultimately use plates with bolts welded to them, from the outside in, through the piece being bolted on, through the laminate (grp or Carbon f) and sandwiching the whole structure with another plate beneath, then washers & nuts. Serious "belt & braces" but we were responsible for people's lives. Great video thank you 👍. Jamie
Easy thing to say with the benefit of hindsight. I can't remember the last time we say a rollhoop detach in that manner. And again, apparently it wasn't the anchoring/glue connecting the rollhoop to the monocoque that gave way, but the carbonfiber of the monocoque itself.
@@GonzoDonzo Did you even watch the video? This is such a strange accident, the roll hoop is tested in other ways, this will and should in time be incorporated into the testing and thus the design requirements of it. Alfa's roll hoop fully complied with the FIA's tests.
@@curnath I don't think the carbon fiber failed, the design did, there obviously was a flaw in the way the layers were laid down if the bonding glue held and it ripped a piece of CF out when I first saw those photos I actually thought that regulations had changed and they did away with roll hoops or they are much lower, since the old test was a stick from the top of roll hoop to the nose of the car, and the drivers helmet mustn't reach the stick, now there is halo doing most of that protection, and the roll hoop is kind of redundant - which this accident kind of proved, it did absorb some of the initial shock though, so perhaps a crumble zone instead of hoop is now more fitting nowdays, and the sides of the halo should be slightly higher so no drivers helmet would ever protrude above it
@@dghtr79_36 Roll hoops are definitly not redundant. There are lots of other ways accidents might happen that would be prevented by it. Just imagine a car running into and over the back of another one at the start. Happened a million times by now. No crumble zone is going to absorb that momentum. Having no roll hoop would mean the drivers would be unprotected from the back. I don't know enough about the crash or the way CF is layered to judge wether that would pose a weakness to this kind of application of force, or if its just that Alpha had some faults in their layering of this particular construction. Seems strange to me, considering it's far from the first time we see a car sliding upside down, but basically never saw the roll hoop detach like that...
Great video, it was one of the first things I noticed first time I saw the replay. I just assumed the extra weight and a full fuel was to much for the roll hoop to handle when momentum enters the equation but I know nothing of the evolution of roll hoops, or if they got beefed up because of the added weight this year. FIA should keep the original test because it seems relevant if there are cars stacked on each other or a car upside down but stationary. Another test should be introduced for more violent shunts with the load coming on more sudden with more directions?
I work in carbon fiber building aircraft and It's amazing how much force it would take to rip it apart like that. It had to exceed at least 150gs to cause that amount of failure. Maybe it's a good thing that it did break because there's no telling where those forces would have traveled.
@@oldfrend he wasn’t weaving. He was slowly closing the gap. Gasly noticed and tried to back out completely. But he was just too late on the brakes catching Russel’s back left which then caused a chain reaction which ended up with Zhou in a crevasse near the catch fence.
Modern gules and adhesive are so strong that the components they are bonded to usually fail before the glue itself. As someone studying Mechanical Engineering on my final 2 semesters, it was cool to see the FEA, it’s kind of our bread and butter. I am curious if a combination of adhesive and mechanical fasteners would prevent this issue.
im surprised with how many are in comments saying George is super dangerous and reckless because they think British media is running to cover for him. Its like the people going after Max for minor mistakes.
@@ethrboy there are 3 players in this accident Zhuo who didn't do anything wrong, Gasly taking a risk to take a gap approaching a corner and George who veered left to setup for a turn. They both caused the accident but nothing out of gross misjudgment but multiple layers of unfortunate coincidences.
I disagree! I have a suspicion and I'm sure I am in the minority that 'The Halo' did not save Zhou. On the contrary - it added to the speed of acceleration ... he was very lucky. It acted as a skid and caused more rotation. I think the gap between the top of the engine housing / air vent would have been more than enough to protect Zhou's helmeted head and actually act as an anchor, dig into the tarmac and slow the car down. Instead it became a missile and could have gone absolutely anywhere. That is only a theory, and is most likely wrong, but it should be put out there all the same. What saved Zhou was the incredible strength and flexibility of the car, not the halo. The halo is a work in progress, and must not be considered a success yet. In certain situations it may cause far more harm than good.
They should consider attaching a lower support section to that hoop that wraps around the monocoque. Build it into the tub as a key structural element? Just thinking out loud .
@@PiousMoltar it took the brunt of the flip and held for a bit as you can see in the track damage. To say it didnt help is bs. The halo saved him during later part of the slide but may not have saved him on it's own with no roll hoop. It did its initial job and just opens the door to more development.
@@UncIe_Drew Yeah, I agree. It seems totally reasonable to conclude that the roll hoop AND halo together kept him safe, and that its not guaranteed that only a halo would have saved him. Oh well, people want to be all angry or conspiratorial or blameful apparently.
Sauber always built really save cars after the accident of Karl Wendlinger in 1994 at Monaco Grand Prix. And I think, they will find out a way to improve their cars as they did same in the past. For me it's totally unbelievable how Zhou survived the landing behind that barrier. That means helmet, halo and the rest of the car still protected the driver enough to get out the wreck without major injuries.
@@kalasmournrex1470 wouldn't ur head just snap off if ur helmet makes contact with the ground at such a speed? Or would it shred? but i feel the latter is unlikely given how mobile and light human body is
Am I the only one getting redirected to ripplesomething channel while clicking on this channel? I also got push notification about their stream, when searching for driver61, the first result is also this ripplesomething. What the fuck?? Edit: No im not :D
That was extremely scary to watch... It seems like some of these recent accidents are getting more violent each time Glad we didn't have em while the halo wasn't here yet some years ago
I feel like the tracks need to be held to higher specifications to meet the 2022 spec cars now, as intensive as the current ones are the cars are clearly getting just a little ahead of them now
Bruh. Do you not remember Canada 2007? That is THE most violent impact I've ever seen on a racetrack. F1 cars have been crashing violently for years. The Halo has protected far fewer than seatbelts, roll hoops, carbon fibre monocoques, and kevlar fuel tanks have. People like to say how many lives the halo saves. It's maybe 4 people in the past 4 years from injury. The HANS device alone has likely saved dozens of drivers from serious crippling injuries or death. An aeroscreen would be a much more visually appealing all-encompassing cheaper solution than our current halo. Btw, the halo would NOT have prevented Massa's injury because that was caused by a small piece of debris which would have slipped through the GIANT holes in the halo.
@@MrJr1976 Yep, that was violent but it's a different kind of crash, not nearly as dangerous cause the car flying around protects the pilot from that massive kinetic energy Even tho the monocoque was damaged it was nothing NEAR just ripping the roll hoop off, that would insta kill Zhou without the halo, that's it Of course a seabelt is more important but there are some crashes where the halo just straight up saves the guy 4 in 4 years isnt good enough? What if we had 4 dead drivers in 4 years? Keep in mind only 2 drivers died in the 80s during official GPs...
@@danielsgrunge 4 drivers saved from injury. Grosjean would have died, Zhou would have lived, whoever it was in Spa would have been injured and Lewis could have died. The reason why Zhou would have lived is the way the cars are designed. If you flipped a formula car upside down, the high part of the nose and the roll bar/intake is generally a straight line above the driver's head. A plexiglass aeroscreen and a roll bar built into frame of the car would be a better combo. And if you wanna get REALLY technical, Grosjean's problem was caused by those stupid Armco barriers that force the drivers to submarine.
Can we all take a moment here and acknowledge that Jules Bianchi’s death is literally the event that saved the lives of Grosjean at Yas Marina, Hamilton at Monza, and now Zhou at Silverstone? Never forget the event at Suzuka that led to this.
I guess the halo will be extended to protect more the driver in case of hook failure. If they mount them together it might pose bigger risk for bigger shocks on the driver, which might kill him. In this crash the car slid in somewhat predictable way, with only the final flip being quite scary, and the road being too close to his helmet.
Halo won't be extended because of the safety compromises. They tested it, any bigger and it would start hampering marshals trying to extract a driver too much from what I've heard. Unfortunately can't make a perfectly safe car, but at least we've reached Safe under most sensible circumstances.
Honestly that crash might've been good for him seeing how fierce he was a week later some racers need to crash to overcome certain fears. Can work both way tho. I'm just glad that cars are safe enough to make sure the drivers survive these experiences.
Great video as always. A little sidestep: did you also notice the new trend in ‘22 that after contact the rim fails and a tyre (and shrapnel from the rim) gets lose from the cars? I guess this is a new safety concern with the new cars (and 17” wheels).
Happened already at Max's crash at Silverstone last year. I haven't seen that in 30 years before, but a couple of times since then. Seems to have started with the introduction of stiffer sidewalls for rear tires mid season last year, and with the 18" rims, now all wheels have these stiffer sidewalls.
The shrapnel we saw from the rim looked like it was just the plastic rim cover (a.k.a. wheel shroud), which quite predictably shattered instantly upon impact. Probably nowhere near as much of a safety concern as the pieces of jagged carbon fibre that regularly break off from the oversized front wings the drivers can't even see.
In the old days the roll hoop or roll cage was one shaped piece of similar material surrounding the driver. Now with the roll bar, a dissimilar material bonded to the C/F, the loads are transferred to the localized portion where the materials are bonded. I worked with C/F for many years and while it has extraordinary strength, its weakest is in shear and seemingly what/where the forces were applied here.
I think this is the first time I saw someone goes upside down and sliding around the track. Watching and listening to f1 commentators made me learn to watch the whole shot, what's going on the background And to see Zhou's car in that condition is really scary
Just in case anyone else out there enjoys Driver61's videos, but doesn't watch the actual races much... Zhou escaped major injury according to what I found. So, all in all, I'd have to say the redundant safety systems worked. The driver is alive and not severely injured.
@@philipcooksey3422 Sure. That’s my (relatively uninformed, and probably poorly expressed) point. The problem appears to have been the bonded carbon delaminating at the interface. So distributing the force over a greater spatial and temporal extent should help with keeping the roll hoop from detaching. Same force yes, but better distributed. The blade seems like it will concentrate the forces into one moment of failure.
@@shibasurfing This is why the blade flares out at the bottom. It's not an issue with the blade design itself - which would mean it should be outlawed. Rather, it's an issue with the mounting which should then be specified in the rules or tested more stringently. Alternatively there could well have been a manufacturing defect. We just don't know yet
@@jameshogge i see what you are saying. That totally makes sense. I guess my question is, does the circular hoop do a better job than the blade of distributing the initial impact over a greater period of time? This would reduce the force. For a blade, it hits the track at once instant. A circular hoop would hit the track and then continue impacting for some time, decelerating it over a greater period of time. I could be completely off-base but it's what popped into my head.
@@shibasurfing I'm not entirely sure it would. If anything, I think you might guess the blade design would be better. Reducing the peak force / spreading out the impulse over a longer period of time would come from flex within the shape of the roll hoop. Both designs would be very stiff in the vertical direction but the blade would be more flexible as soon as there is a lateral component to the force thereby cushioning it a bit? Then again, that is also a very double edged sword: flexibility in the bonded region may allow it to peel up from one edge - essentially only one edge of the join will take all of the force and it will tear away from that point. That would be my hunch anyway. Of course its incredibly difficult to guess how stiff these structures are - especially since they'll have complicated internal geometries to maximise the strength while keeping weight low. That's what the FEM analysis will be used for
Surprised there was no mention of the similar accident Pedro Diniz had in 1999 without the halo where he got flipped at the Nurburgring and the roll hoop also failed. I honestly don’t think the Halo made as much of a difference as people assume having witnessed Pedro’s accident back in 1999 where its reasonable to say Pedro had a bigger impact once the roll hoop came off.
I just watched that other crash and my impression was that DIniz wasn't going as fast, but I'm not sure. It would be an interesting comparison if we had the telemetry data in detail.
Failure sounds like 'sheer' induced by tension. Load forces on roll structure transmitted to bonded area on monocoque. Layers of carbon fiber do not have much resin in between. When parts are formed, resin is introduced while part is in vacuum bag. Part then goes to autoclave where vacuum and heat cures resin. Many layers are supposed to become a single part, but weakness between layers remain. Lots of resin on top and bottom, not so much between layers. There can be many layers depending on requirements, so many little weaknesses hiding under surface.
Great content as always! I don't think the FIA needs to depart from static testing versus just understanding all of the likely directions that the hoop could be loaded. It was an unusual event how the car rolled and I think the more likely culprit of the failure boils down to assumptions on the magnitude and direction of force (which is more of a kinematics problem). Teams already use FEA to design most if not all parts since it's been around for a long time.
Something amusing/interesting to ponder: Some of the very earliest forms of pottery is taking clay, rolling it into long thin pieces, then layering them to form the shape of something akin to a vase. Contrast this with wheel turned stuff later on and you see the main difference is that the former is additive the latter is subtractive (if you will). The modern day 3D printed stuff like talked about in this video is really a high tech version of that technique which itself is only slightly younger than dirt.
I agree that gasly Needs to be more careful, but I feel like in this situation it wasn’t gasly’s fault. Russel should have seen him and if you watch the crash you can actually see gasly trying to brake out of the situation.
Relying on the carbon fibre to hold such an important safety item is just DUMB ! The adhesive is only holding onto the outer layer of CF, and that later is relying on the inter-layer bonding strength. The correct system of attachment should be bonding AND mechanical through bolts with anti-pull through pads. This accident highlights the shortcomings of this design and will surely lead to improvements. Great video.
now that is very interesting, and something that due to the materials involved, would be of great interest to airplane and rocket manufacturers. great vid Scott and crew. B)
Great video, super informative and as always Scarbs makes it easy to understand. I'm guessing 3d-printing the entire car out of titanium is out of the question though.
What would probably help is in addition to the 3-axis force test to do 1) a "torgue test" where you apply force from opposite sides on opposite ends and 2) a "rip test" where you apply force on the front top end in the upwards and rear direction. This would properly test the bonds and carbon fibre in their weakest links. If you wanna be extra fancy/safe you would do all 3 tests with static and dynamic forces.
2018 Monza: in FP2 Ericsson crashed the Alpha spectacularly. Although the roll hoop stayed intact there, because of the lighter cars and the not full fuel load. It's worth to watch, you can see the full structure of the actual roll hoop, not only the drawing.
@@gabormiklay9209 And Merc has won races using about 85 kg. Just because max fuel is 110kg doesn't mean they fill it to the brim for every race, and Silverstone is not a fuel heavy race. The load imparted on that roll hoop and the direction it was forced in would have caused it to fail even on empty tanks. In the 2018 Monza crash the roll hoop hit dirt, and not the track. Pay better attention buddy.
@@byanymeansnecessary9329 Still, at around 200 KPH (Zhou's speed before turning upside down) 90 KG is significant. Also: roll hoops are designed to hit tarmac (because what else could and upside down racing car hit first).
So glad him and Alex are ok. Blows my mind how far the cars have come and how zhou was perfectly fine.
No doubt. An accident like that would have been fatal as recent as the 1990s.
Absolutely. I'm so relieved there's redundancy between all the safety systems. Halos save lives.
i was shocked seeing him walk around the paddock like normal towards the end of the race. Thank god for all the safety measures that saved Zhou's life.
yeah sure but that's to be assumed. in a similar time period rally cars have improved beyond this to a point where you can just send a WRC car into a ditch at 100 mph and the rollcage will keep you safe. formula 1 cars of course cannot have such a huge cage around them but my point is I don't think that crash was so bad that you couldn't survive it in a top spec fully modern race car of any sort
@@kalasmournrex1470 Would have been fatal in 2017
Let's appreciate that even though the result of this accident is that the driver is able to compete less than a week later, we are still pushing for safer cars.
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@@alunesh12345
this was all mechanical engineering masterclass in a league of its own, don't even attempt to pull that Jesus bullshit into this matter because he doesn't exist and it is all lies.
safety has to first, second, third, ... and last. anything that even has the potential to jeopardise any safety should be top priority for all regulators and officials. if this blade style roll hoop has any sort of weakness, then raise the standards. safety improvements should be as maximalist as possible. i don't ever want to hear news of an F1 driver getting killed in a race ever again... not even any serious injuries.
on that note, sausage kerbs need to be eliminated.
And tracks too! How the car got stuck was horrifying. If there had been fire omg.
@@alveolate literally just don't go off track and the sausage kerb won't hurt you lol (this is a joke)
Once again the halo proved that it saves lives, it was one of the best inventions in Formula 1
Wouldn't have saved 4 out of 20 drivers in the current grid, though. Taller drivers heads protrude over the halo line and they wouldn't be able to duck when inverted, bounching violently and HANS device restricts forward movement. And a few more drivers would have their helmets touching the tarmac as well. Luckily Zhou happens to be one of the more average sized drivers.
F-1 has been improving safety for years - tech used in other racing and domestic cars as well.
@Goat Exactly, that's why the roll hoop is the principal roll structure. But it snapped off and halo has the secondary roll stucture role. But those taller drivers would have been severely injured in an identical scenario.
🙌Charlie Whiting 🙌
@@kekkonenprkl
Is there a specific height for the halo? As a primary safety device, I would think that the regulation would require a “minimum height above helmet”
Sounds as though you know more than I do since I didn’t even think about driver height - just wondering
I always thought that the roll hoop was part of the monocoque just like the halo. Thanks for this vid to clear this up!
Both it and the halo are not part of the monocoque. They can’t be - they’re made of titanium while the monocoque is a carbon honeycomb composite. Both have to be attached to the monocoque with either glue or fasteners.
It should definitely be
Unfortunately, a carbon fiber roll hoop would just get worn away really quickly. Carbon fiber is very strong but hardly abrasion resistant enough and would still deal with the delamination (layers coming apart) issues
If you think about it, it is, it's glued but all of the carbon layer are glued toghether aswell
@@tedt7991 that would be extremely dangerous
I find it incredible that just 4 years after the highly contentious introduction of the halo, the number of lives saved and injuries prevented across open wheel categories is staggering. Zhou can consider himself one of the lives saved.
If i remember right it was:
- Leclerc
- Zhou
- Hamilton
- Grojean
did i miss anyone (counting only F1 here but in F2 and F3 there were also other lives saved)
@@burnstick1380 Hamilton? Nah the standard hoop would have saved him anyway
@@rnichol22 Verstappens car slipped over the hoop into the halo, without the halo it's quite likely that Verstappens rear right tire would have landed on Hamiltons head, which probably would have caused some injuries if not fatal ones.
@@burnstick1380
"probably" 700kg dropped on your dome is 100% lethal
@windrose5988 it is not necessarily about the rotation of the rear tires but rather the weight. Most of the cars weight would have dropped down on hamiltons head which quite likely would have broken his neck or similar injuries
You're spot on about "welding glue" used in F1 being so strong, it's actually stronger than welding and is the same as used in the aeronautics industry and was developed to replace welding or riveting in low drag aircraft such as stealth planes so has to be able to withstand pressure at mach III plus.
Don't get in on your fingers! And ask a parent to help....😵
I don't know what glue you've worked with, I work in the aerospace industry on spacecraft and glue (like EA9394) is pretty weak, certainly when compared to welding. As with all fastening methods it's obviously more than just the tensile strength of the component, and that's where glue is nice since you can put a large bond line on something. But with the same area of welding and bonding, I'm not aware of any glue that is stronger than a 70ksi weld.
@@TheSnivilous scotchweld is pretty strong🤷♂️ theyre probably talking about the epoxies used for composites when you do a wet lay up, that shits really strong
and the rail industry. there are many cases where you have to bond two different metals and welding is not viable.
The almost comical part is it's basically super glue. And yup that's what they use on fighter jets.
With how carbon works, it's likely that the initial vertical drop on the roll hoop caused the initial delamination of the carbon fibre layers in the monocoque, which then led to the carbon fibre being weakened and made it easy to tear off. Kinda scary looking at it, but it's good to see him walking and alive.
And it was being ground away by the tarmac.
@@stpbasss3773 Grounded away? More like torn off by the tarmac. The end of the line dug into the tarmac was probably the point where it tore off
Ya.. no matter how many layer your carbon fibre has.. the roll hoop is bonded on the 1st layer only..
@@stpbasss3773 Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😗❤️😁❤️😚
@@stpbasss3773 did you even watch the video?
Great video. It looks like they need to anchor it in new ways. Maybe a combination of screws and bonding lower down in the chassis. They also need to look at the fencing. The scariest part of the accident was the gap that the car got stuck in. There’s no way Zhou could have survived a fire like Romans and the car was fully loaded with fuel.
I think Grosjean's crash saved Zhou. FIA apparently learned from Grosjean's incident and implemented new fuel tank design requirements for this year's new cars to reduce the chance of the fuel tank being ripped apart and catching fire.
I actually think the gap is less of an issue than the surface of the runoff area beneath the gravel. There's a ledge before the tyre wall which is what launched the car.
Either no gap at all, with escape/entry windows/gaps in the fence for marshals and/or drivers to pass through. Or a gap wide enough, so a car can't get stuck sideways in the narrow trench like it did.
@@kekkonenprkl apparently they need a gap as a buffer zone for the barriers to move inwards in case of a more common front collision. They never expected a car to flip over the barriers. I think a wider gap would work if space allows.
@@willw.3366 Didn't realize the tyre barrier is required to be able to move inward, as the tyres are stacked against a low, probably a meter high steel barrier. But it makes sense. So i assume that steel barrier is designed to deform at a certain rate, to make the tyre wall stiff enough for the initial impact but to allow them to move and release energy right after? I agree, a bigger "trench" would be the way to go then.
The thing I absolutely love about mechanical engineering is just how much you can learn when designs fail. I'm very happy Zhou walked away from this incident and because this critical safety part failed, it will be redesigned in hopes that it never does again.
The safety part didn't fail, the carbon fiber it was attached to failed. In order to prevent this again, it will take a drastic change in regulations and design. It would take something more akin to a "roll cage" around the cockpit to prevent such an event; something all the way to the floor of the chassis. The carbon fiber will always be the weakest link.
@@Parker-- Ah remember when cars started getting bigger and heavier and everyone was on board with it because of "safety", it is so ironic that those bigger and heavier cars behave in dangerous ways during cashes. When cars where lighter roll structures didn't crumble so easily and cars just flipped again instead of sliding upside down.
@@Ale-nv2bo There's always give and take and all the rules regarding everything else are arbitrary to begin with. If they want to make a legitimate change so that the car is safer in this situation again it will take a drastic change. Of course, the question is do they actually want to make such a dramatic change for safety? Who knows. They could just as easily shrink the cars back down, still add a roll cage and keep the speed by changing engine specs and a billion other arbitrary rules if they wanted to. It's a matter of if they actually want to.
@@Parker-- Amen to that brother. Unlike steels, there is no failing by degrees in carbon fiber. Its 100% to 0 % in a instant.
@@Ale-nv2bo Surely you would rather be sliding in a car with a feature to stop your head getting hit than being in a car that’s flipping with no feature
It was shocking seeing Zhou’s car being tossed around and dragged on the track and then stopping at the tire barrier. I watched it live on F1TV, and I couldn’t believe it when the accident happened. I’m glad that Zhou came out ok from this accident. It could’ve been so much worse. Thank you for the excellent breakdown, Scott!
Was anticipating you putting out a video on this. Much appreciated. So glad Zhou and Alex are ok!
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@@alunesh12345 nah sorry
When I was doing them there was the combined static test and there was a reverse theoretical test that you passed by proving your calculations in FEA. The latter was very often, er, well, extra material is extra weight and up there it heavily effects your CoG, so yeah, the reverse test calcs were perhaps wishful thinking.
Also bears mentioning that the hoop passes ONLY this combined test, swap the values around, change the values, worn't pass. Remember the old side crash tubes? Literal tubes at 90deg to X? Literally only worked along their axis, hit the barriers slightly oblique and they were useless. The cars are designed within the rules with no consideration to driver safety, dirt truth. The rules need to consider this, always. However, no-one will stand up in the TDs meetings and say "we know our car is unsafe in situation X, please change the rules".
Thank God drivers are OK. Incredible accident and very interesting videos with lots of explanations for us the regular viewers.
It's called a halo 😇 but it was engineered as every other part of the cars, so thanks engineers for drivers being OK 😉
Don't thank god. Thank the engineers.
Mom: Did you fail another test?
Scarbs: I didn't fail the test, I departed from passing it.
I was thinking the exact same thing.
Thanks Scarbs! I've been thinking exactly the same thing, the FIA does test these roll hoops thoroughly but the bonding with the chassis is what most likely failed. The FIA should look into it, but as the tests stand now, the roll hoop met specifications.
Just like any assembly, the bonding point is where the structure usually fails.
Nah, it's much more likely that the carbon fiber layer it was bonded too sheered off. As mentioned, carbon fiber is not resistant to forces along the layers. This is why Lamborghini and their partners created Forged Carbon Fiber that has similar strength in all directions (though I believe less strength than traditional carbon fiber has against the weave).
@@jkliao6486 Not with carbon fiber.
@@kalasmournrex1470 You can clearly see leftover adhesive from photos. If it was only the carbon fiber there would be none because the roll hoop would have ripped the whole layer off
@@kalasmournrex1470 It is still the bonding point though.
A great video again from Driver61.
What I have learned from my co-workers ( one has done a Ph.D. in how to repair metal fractures of the airplane with glued composite plates) is that bonding is a much better way to connect parts than glue and bolted connections, less stress, and no weak points.
I do a lot of fea calculations for rollover structures with implicit and explicit code, at this point for big machines, for example, the vertical load can be 100 tonnes.
I do prefer explicit code because it allows progressive damage model to steel and weld structures and their alloys, to design lighter structures than implicit code.
yeah only problem with the glued composites is that for the calculations it is harder to define how the loads gets turned over. As for bolted/riveted (bolts are rarely used) connections you can to that way easier.
In the c ase here i would suggest hat the adhesion between comb and top layer of the carbon failed. Therefore a bolted connections would improve that. because then the load would be applied to fully use the strength of thestructure. It also would help becuase such impacts can cause delamination which then weakens the carbon
I was wondering and if you could answer wonderful, and if not, maybe you could ask your friends:
Could it be that the initial vertical impact damaged the carbon composite debilitating the bond between the top layers and the rest of the monocoque? Then, the sliding after could have caused the debilitated structure to detach?
Could this happen to an up to spec part or maybe it suffered from defects during manufacture? It is my understanding that small imperfections in composites are both easy to appear during manufacture and hard to detect.
@@andresmartinezramos7513 I comes down how its all layered up. I dont know if they use a core for example or ift its just layers of CFRP. If its done with a core im sure the weak point is between core and the first layer of the net.
Is it possible that the “blade” style resulted in greater shear stress by digging into the track? A more rounded hoop would have perhaps been subject to lower sideways force as the car slid across the surface.
Yes indeed.
That tracks, I suspect we may see a ban on the blade style roll hoop, but I suppose we'll have to wait for the official investigation to bring all the facts and findings and a recommendation.
Like using a baseball bat to remove a barnacle versus a mailbox
sheer stress is not gonna cause delamination of the carbon
i think that you might be on to something
how the roll hoop is fixed to the car should be looked at. a larger surface area when bonded to the chassis or better integration into the monocoque
Or if it's the carbon that failed... maybe the whole titanium structure of the roll hoop should have... "tendrils" as it were, reaching out deep into different parts of the monocoque, rather than just being a small flat surface stuck to it.
@@PiousMoltar Even a few simple bolted connections in addition with the usual adhesive would prevent the top most layer of the carbon structure being subjected to all of the stress and tear away. The adhesive is strong enough, but the strength is limited to the layer strength it's directly bonded to. A few bolts would relieve some of that stress to a thicker area/volume of the structure.
But they haven't done that because they aren't required to, as long as they pass the tests, they will use a method that saves most weight. But it wouldn't add much weight to the car if it became mandatory to add some bolted connections there, especially if a more exotic alloy would be used. Not for the current season though, can't really require them to update their monocoques with the current budgets until next year.
@@kekkonenprkl Agreed. No need to reinvent the wheel here. Add some bolts in addition to the bonding they already use.
@@kekkonenprkl yeah and a plate on the other side to bolt into, just the bolts would not add that much strength because they would rip right through the carbon, but a larger brace or plate would require every carbon strand to snap, as well there should be carbon string layer in a sort of U shape imbedded into the carbon around the holes so that the bolts can’t slide and rip through the carbon, also keeping the adhesive
agreed, looks from this that the flat surface the roll hoop is bonded to has layer lines only on a single xy plane... an improvement could just be to bond to surfaces on the xz and yz planes as well, at least that way if one fails there are 2 other planes of layer lines to hold it.... i am not a composite expert, but it makes sense in my head!
Thanks for putting that together, was wondering what happened to the roll hoop there. Was so surprised to see only the halo keeping his head off the ground.
Hurts to think of what could've happened without the halo - the back of the car would've still been some protection as the front tips up, but his helmet would've been dragging for sure and who knows what injuries or worse could've happened.
The picture seems to show left over adhesive (those reddish spots that are left behind), so I'm not so sure that it was the carbon fiber alone, but certainly some of the adhesive clearly failed too.
I'm actually beginning to wonder if there was improper surface preparation on the monocoque: large regions of the adhesive were removed in their entirety which could suggest it had failed to properly bond to the carbon fibre.
@@jameshogge yet more to suggest a return to how it was done for last 50+ years without many issues. Even if the “new is better” brigade still want to glue the roll hoop on, why not use bolts too?
@@testpilotian3188 the glueing method spreads the load evenly, while the bolts method apply very strong pressure points right where the bolts are located, and also weaken the carbon fibre itself since you need to drill holes in it. I do not see a better solution other than increasing the amount of carbon surface woven into the roll hoop
@@Shiinamusiclyricssubs well don't bolt it to carbon fibre then because it breaks so easily.
@@Shiinamusiclyricssubs You would want to go the other way: carbon integrated into the roll hoop would break (its too stiff, you need something compliant to absorb energy) at the first deformation leaving just the titanium.
no way these got hacked someone get the FIA on this now 😭😭😭 or maybe it was them
As a design engineer who has worked in aerospace composite design I have the following comments. Firstly this component took loads that were not envisaged st the concept stage. Secondly, while bonding is excellent,I think thos should be attached to the structure underneath better. Increased load paths and mechanical as well as bonded attachments.
Im surprised the Roll Hoop is not a more integrated part on the car. Instead of it being built into the monocoque, its just placed on top....not surprised it failed the way it did.
Carbon fiber would be a poor material to build a roll hoop out of. There are reasons they are made from titanium. And with that you have to connect the materials in some way.
And again, I can't remember the last time we saw a roll hoop detach like that.
Indeed!
It SHOULD be surprising. With hindsight, it may seem obvious but the tests place very large loads on the region and provide a lot of evidence to suggest it is OK.
My bets are actually on a manufacturing defect at this point. Improper preparation of the monocoque before bonding the roll hoop to it.
It really can't be made to be more apart of the car other than to have some spikes that go into the monocoque and are also glued in along with the other glue
Carbon fibre is just thin sheets stuck on top of each other.
Resins are very strong
I had imagined the roll hoop to be an integral part of the chassis and not just stuck on, this illustrates the teams are putting weight and performance before driver safety.
Amazing explanation, easy enough to understand, and in depth enough to not confuse! top notch!
B sport’s video from yesterday is much better (and coming from an actual f1 engineer). Highly recommend, just as all the rest of his content.
1:36- I hated the idea of the halo when it came out but, seeing this perfectly timed pic proved me wrong again. I don’t think Zhou would be alive or at the very least be able to walk if it hadn’t been for the halo. That said, maybe over the past few years the drivers have become a little too cavalier due to the cars being all but death proof at this point.
I don't think so. Racing drivers achieve the limit no matter the risk, within reason.
I don't believe "able to walk" fits into this equation. Without the halo, his head would have been severed. Walking without a head is not an option.
The cars aren't "death proof." That's the kind of ignorance and complacency that'll get drivers killed. Even if you think you've planned for every eventuality, there are still going to be things that you likely haven't accounted for. Murphy's Law: anything that can go wrong will go wrong.
@@CaseyCollier didn’t say that they were.
@@wunkskorks2623
You said, "all but," meaning that you think they're nearly "death proof." That just simply isn't the case, which is why I pointed out the flaws in that thinking.
Seems like the channel got hacked or something
Huge congratulations for this video and your analysis: it was very interesting, really detailed and technically flawless.
Thank you so much for helping us in better understand these techical topics.
I think that the design needs to be updated to have the actual roll-hoop extend much more below the current 'bonding' area ...The potential for such awesome and variable dynamic loads/stresses cannot all be accounted for ...and now that the authorities see that there is actually a failure point still present(bonding intersection in this case), they can do some updates. Extend the Roll-hoop 2, 3 or even 4 times lower into the Tub superstructure(even bonding it with the Tub structure at several points on different planes maybe?)
...I'm just so happy that Zhou was able to survive this one!
Perfectly said.
thought they were designed to deflect lose tires, not roll over protection because like you said, low center of gravity makes overturns very rare ...the monocock intake handles rollovers
I find it very odd that they are allowed a blade style hoop, or even a two-leg design. Zhou's crash showed one of the biggest issues with lab testing: the real world is much crazier. As it spun upside down, it essentially wiggled the blade and seemed to have broken the carbon. A four leg design most likely would've lasted a lot longer, as it can disperse the load across a much larger area.
It is also surprising it is just bonded on top, instead of being made an integral part. The entire monocoque is handmade, so integrating it would be possible. Given how important it is, it would be a good way of retaining the hoop in an upside down slide.
Exactly
Doesn't seem like rocket science does it. I agree, a 4 leg design seems like a no brainer. As for the testing.. Why they used a static load test for a part destined to experience impact, is a real head scratcher.
@@M3rVsT4H Same reason helmet makers test their helmets in static form: it would never pass a dynamic test.
The latest standard in MotoGP is the first to do dynamic and random testing, coming closest to a real world scenario.
@@Yvolve Now helmets I get. Wherever big profits are to be found, you will find shortcuts. But nobody gains from this... Other than just not wanting to crash test such an expensive monocoque.. I can't think of a reason why you wouldn't just test thoroughly. but oh well, I guess that's why they get paid the big bux.
That wouldnt hae made a difference. the mono is essentially a composite of carbon fibre and a comb between the layers. What happened here is that it sheared at the comb so the top side was gone but bottom side was intact. Thats the biggest problem if oyu glue it. You get the weakest point between the layers and the comb. if you bolt the roll hoop the differs. not the bolt is hold underneath the whole therefore it is way more resitant to shearing.
Hot take: The roll hoop should be a standardized part built using tried and true methods. There is no need to allow the constructors to design their own. Its a matter of driver safety and if everyone has the same part the competition won't be affected.
I think the halo and the roll hoop should be designed to be one piece, to prevent it to snap like in this case.
I used to build yachts and bonding parts to parts was on the increase to save 'through bolting'. However, we had delamination problems too. If a part failed, the naval architects would put plate (ply or metal plate) beneath for strength. Then ultimately use plates with bolts welded to them, from the outside in, through the piece being bolted on, through the laminate (grp or Carbon f) and sandwiching the whole structure with another plate beneath, then washers & nuts. Serious "belt & braces" but we were responsible for people's lives. Great video thank you 👍. Jamie
i've been saying it should be made of titanium when it already was, but i will say it needs to be better anchored to the safety cell
Easy thing to say with the benefit of hindsight.
I can't remember the last time we say a rollhoop detach in that manner. And again, apparently it wasn't the anchoring/glue connecting the rollhoop to the monocoque that gave way, but the carbonfiber of the monocoque itself.
@@curnath and wtf is the fia doing if their tests are so extensive and yet alpha romeo still got the chassis approved?
@@GonzoDonzo Did you even watch the video? This is such a strange accident, the roll hoop is tested in other ways, this will and should in time be incorporated into the testing and thus the design requirements of it. Alfa's roll hoop fully complied with the FIA's tests.
@@curnath I don't think the carbon fiber failed, the design did, there obviously was a flaw in the way the layers were laid down if the bonding glue held and it ripped a piece of CF out
when I first saw those photos I actually thought that regulations had changed and they did away with roll hoops or they are much lower, since the old test was a stick from the top of roll hoop to the nose of the car, and the drivers helmet mustn't reach the stick, now there is halo doing most of that protection, and the roll hoop is kind of redundant - which this accident kind of proved, it did absorb some of the initial shock though, so perhaps a crumble zone instead of hoop is now more fitting nowdays, and the sides of the halo should be slightly higher so no drivers helmet would ever protrude above it
@@dghtr79_36 Roll hoops are definitly not redundant. There are lots of other ways accidents might happen that would be prevented by it. Just imagine a car running into and over the back of another one at the start. Happened a million times by now. No crumble zone is going to absorb that momentum. Having no roll hoop would mean the drivers would be unprotected from the back.
I don't know enough about the crash or the way CF is layered to judge wether that would pose a weakness to this kind of application of force, or if its just that Alpha had some faults in their layering of this particular construction. Seems strange to me, considering it's far from the first time we see a car sliding upside down, but basically never saw the roll hoop detach like that...
Fantastic analysis and explanation yet again, keep up the great work
Great video, it was one of the first things I noticed first time I saw the replay. I just assumed the extra weight and a full fuel was to much for the roll hoop to handle when momentum enters the equation but I know nothing of the evolution of roll hoops, or if they got beefed up because of the added weight this year. FIA should keep the original test because it seems relevant if there are cars stacked on each other or a car upside down but stationary. Another test should be introduced for more violent shunts with the load coming on more sudden with more directions?
Very clear and concise video of incident. Leaned a lot from this. Thumbs up.
Certain pictures of the car hanging in the fence show red glue still attached to the monocoque. My suspicion is that the glue did fail.
However the Halo did what it was there to do.
I work in carbon fiber building aircraft and It's amazing how much force it would take to rip it apart like that. It had to exceed at least 150gs to cause that amount of failure. Maybe it's a good thing that it did break because there's no telling where those forces would have traveled.
Just a note: Gasly attempted to get out of the way he braked a bit too late to get out of there.
russell shouldn't be weaving around when it was obvious he got a terrible start and cars were passing him.
@@oldfrend he wasn’t weaving. He was slowly closing the gap. Gasly noticed and tried to back out completely. But he was just too late on the brakes catching Russel’s back left which then caused a chain reaction which ended up with Zhou in a crevasse near the catch fence.
Modern gules and adhesive are so strong that the components they are bonded to usually fail before the glue itself. As someone studying Mechanical Engineering on my final 2 semesters, it was cool to see the FEA, it’s kind of our bread and butter. I am curious if a combination of adhesive and mechanical fasteners would prevent this issue.
I think an actual rounded hoop would have worked and not dug into the tarmac as much
Is this based on any kind of actual evidence or calculation?
Many thanks for the review and explanation. Best wishes from NZ.
im surprised with how many are in comments saying George is super dangerous and reckless because they think British media is running to cover for him. Its like the people going after Max for minor mistakes.
he literally caused a terrible accident but go off
Having brain doesn’t mean having the same inteligent level like the rest..
Oh we got one here xD
@@ethrboy there are 3 players in this accident Zhuo who didn't do anything wrong, Gasly taking a risk to take a gap approaching a corner and George who veered left to setup for a turn. They both caused the accident but nothing out of gross misjudgment but multiple layers of unfortunate coincidences.
Haven't seen a single comment saying this anywhere. Anyone who does is probably a clown
@@Cecil97 no. it was George's fault 100% i bet you it was intentional
Great video, thank-you to everyone involved, it is greatly appreciated🙌❤️🙌🤘💖
I disagree! I have a suspicion and I'm sure I am in the minority that 'The Halo' did not save Zhou. On the contrary - it added to the speed of acceleration ... he was very lucky. It acted as a skid and caused more rotation. I think the gap between the top of the engine housing / air vent would have been more than enough to protect Zhou's helmeted head and actually act as an anchor, dig into the tarmac and slow the car down. Instead it became a missile and could have gone absolutely anywhere. That is only a theory, and is most likely wrong, but it should be put out there all the same. What saved Zhou was the incredible strength and flexibility of the car, not the halo. The halo is a work in progress, and must not be considered a success yet. In certain situations it may cause far more harm than good.
Not picking a fight here but the front of the hoop has scour marks and sparked like the Fourth of July. He’d be headless with out it. Lucky man.
Front of the halo I meant. Stupid autocorrect induced spelling errors.
They should consider attaching a lower support section to that hoop that wraps around the monocoque. Build it into the tub as a key structural element? Just thinking out loud .
Great video. I wish it was longer. My question is did Zhou’s helmet ever make contact with the track?
The fact he just walked out proves it didn't fail. These things are incredible in every way
Um, the fact he walked was because of the halo and just plain luck. The roll hoop was gone. It was not helping.
@@PiousMoltar it took the brunt of the flip and held for a bit as you can see in the track damage. To say it didnt help is bs. The halo saved him during later part of the slide but may not have saved him on it's own with no roll hoop. It did its initial job and just opens the door to more development.
@@UncIe_Drew Yeah, I agree. It seems totally reasonable to conclude that the roll hoop AND halo together kept him safe, and that its not guaranteed that only a halo would have saved him. Oh well, people want to be all angry or conspiratorial or blameful apparently.
Sauber always built really save cars after the accident of Karl Wendlinger in 1994 at Monaco Grand Prix. And I think, they will find out a way to improve their cars as they did same in the past. For me it's totally unbelievable how Zhou survived the landing behind that barrier. That means helmet, halo and the rest of the car still protected the driver enough to get out the wreck without major injuries.
FIA needs to investigate how this channel got hacked, but how will this affect lewis’s straight line speed from a slow corner??!
Wow. Excellent video. Very informative. Thank you.
Zhou must have been terrified. That would have been a fatal not so long ago
Outstanding presentation! Well done!
1:57 Wouldn't it be better if the top of the helmet didn't extend past the halo? It swoops low towards the back.
Yeah that's exactly what I was thinking!
Yea, if that was Ocon or George in the car, it wouldn't have been such a good outcome.
@@scottmcqueen3964 Maybe, maybe not. You can lose quite a bit of your helmet and still be ok.
@@kalasmournrex1470 wouldn't ur head just snap off if ur helmet makes contact with the ground at such a speed? Or would it shred? but i feel the latter is unlikely given how mobile and light human body is
The gap between the halo and the roll hoop is intended for driver to escape during emergency I guess
I love having Scarbs look at this kind of issue. Explained so well!
Am I the only one getting redirected to ripplesomething channel while clicking on this channel? I also got push notification about their stream, when searching for driver61, the first result is also this ripplesomething. What the fuck??
Edit: No im not :D
They got hacked
@@edvinobing3576 thank you, for second i thought that my vanced app got crazy
That was extremely scary to watch... It seems like some of these recent accidents are getting more violent each time
Glad we didn't have em while the halo wasn't here yet some years ago
I feel like the tracks need to be held to higher specifications to meet the 2022 spec cars now, as intensive as the current ones are the cars are clearly getting just a little ahead of them now
Bruh. Do you not remember Canada 2007? That is THE most violent impact I've ever seen on a racetrack. F1 cars have been crashing violently for years. The Halo has protected far fewer than seatbelts, roll hoops, carbon fibre monocoques, and kevlar fuel tanks have. People like to say how many lives the halo saves. It's maybe 4 people in the past 4 years from injury. The HANS device alone has likely saved dozens of drivers from serious crippling injuries or death. An aeroscreen would be a much more visually appealing all-encompassing cheaper solution than our current halo. Btw, the halo would NOT have prevented Massa's injury because that was caused by a small piece of debris which would have slipped through the GIANT holes in the halo.
@@morgan200three I get that same feeling
@@MrJr1976 Yep, that was violent but it's a different kind of crash, not nearly as dangerous cause the car flying around protects the pilot from that massive kinetic energy
Even tho the monocoque was damaged it was nothing NEAR just ripping the roll hoop off, that would insta kill Zhou without the halo, that's it
Of course a seabelt is more important but there are some crashes where the halo just straight up saves the guy
4 in 4 years isnt good enough? What if we had 4 dead drivers in 4 years? Keep in mind only 2 drivers died in the 80s during official GPs...
@@danielsgrunge 4 drivers saved from injury. Grosjean would have died, Zhou would have lived, whoever it was in Spa would have been injured and Lewis could have died. The reason why Zhou would have lived is the way the cars are designed. If you flipped a formula car upside down, the high part of the nose and the roll bar/intake is generally a straight line above the driver's head. A plexiglass aeroscreen and a roll bar built into frame of the car would be a better combo.
And if you wanna get REALLY technical, Grosjean's problem was caused by those stupid Armco barriers that force the drivers to submarine.
One of your best recent videos.
Geez got channel hacked by crypto lowlives
FANTASTIC VID ! AS USUAL ! /// Scarbs is a master as well !
This is one of the reasons I love F1, the science behind it. Great video once again.
Can we all take a moment here and acknowledge that Jules Bianchi’s death is literally the event that saved the lives of Grosjean at Yas Marina, Hamilton at Monza, and now Zhou at Silverstone? Never forget the event at Suzuka that led to this.
absolutely incredible video man!
I guess the halo will be extended to protect more the driver in case of hook failure. If they mount them together it might pose bigger risk for bigger shocks on the driver, which might kill him. In this crash the car slid in somewhat predictable way, with only the final flip being quite scary, and the road being too close to his helmet.
The Halo saved him 100%
Halo won't be extended because of the safety compromises.
They tested it, any bigger and it would start hampering marshals trying to extract a driver too much from what I've heard.
Unfortunately can't make a perfectly safe car, but at least we've reached Safe under most sensible circumstances.
Ultimately, this was a spectacular success story for the Halo.
Honestly that crash might've been good for him seeing how fierce he was a week later some racers need to crash to overcome certain fears.
Can work both way tho.
I'm just glad that cars are safe enough to make sure the drivers survive these experiences.
brilliant job of explaining this crash
It looked like Zhou’s helmet dragged along the track too. I wouldn’t be surprised if his helmet was full of gravel.
It didn’t. Pictures showed the helmet undamaged when he took it off
Great video as always. A little sidestep: did you also notice the new trend in ‘22 that after contact the rim fails and a tyre (and shrapnel from the rim) gets lose from the cars? I guess this is a new safety concern with the new cars (and 17” wheels).
Happened already at Max's crash at Silverstone last year. I haven't seen that in 30 years before, but a couple of times since then. Seems to have started with the introduction of stiffer sidewalls for rear tires mid season last year, and with the 18" rims, now all wheels have these stiffer sidewalls.
The shrapnel we saw from the rim looked like it was just the plastic rim cover (a.k.a. wheel shroud), which quite predictably shattered instantly upon impact. Probably nowhere near as much of a safety concern as the pieces of jagged carbon fibre that regularly break off from the oversized front wings the drivers can't even see.
Channel has been hacked 😶 Hope they can sort this out
In the old days the roll hoop or roll cage was one shaped piece of similar material surrounding the driver. Now with the roll bar, a dissimilar material bonded to the C/F, the loads are transferred to the localized portion where the materials are bonded. I worked with C/F for many years and while it has extraordinary strength, its weakest is in shear and seemingly what/where the forces were applied here.
B Sport (ex Force India) did a video on this. He had a good look and it was the 'Glue' that failed.
I think this is the first time I saw someone goes upside down and sliding around the track. Watching and listening to f1 commentators made me learn to watch the whole shot, what's going on the background
And to see Zhou's car in that condition is really scary
WTF ...how come there are 7.6 thousand likes on the live
The halo absolutely did its job protecting the driver and likely caused the failure of the roll hoop.
bro the channel got hacked😂😂😂
Just in case anyone else out there enjoys Driver61's videos, but doesn't watch the actual races much...
Zhou escaped major injury according to what I found. So, all in all, I'd have to say the redundant safety systems worked. The driver is alive and not severely injured.
The whole “blade roll hoop” concept seems suspect to me. It will by definition transmit a huge lateral force.
By definition, any shape would transmit the same amount of load, its just distributed differently. That's how statics works
@@philipcooksey3422 Sure. That’s my (relatively uninformed, and probably poorly expressed) point. The problem appears to have been the bonded carbon delaminating at the interface. So distributing the force over a greater spatial and temporal extent should help with keeping the roll hoop from detaching. Same force yes, but better distributed. The blade seems like it will concentrate the forces into one moment of failure.
@@shibasurfing This is why the blade flares out at the bottom. It's not an issue with the blade design itself - which would mean it should be outlawed. Rather, it's an issue with the mounting which should then be specified in the rules or tested more stringently.
Alternatively there could well have been a manufacturing defect. We just don't know yet
@@jameshogge i see what you are saying. That totally makes sense.
I guess my question is, does the circular hoop do a better job than the blade of distributing the initial impact over a greater period of time? This would reduce the force. For a blade, it hits the track at once instant. A circular hoop would hit the track and then continue impacting for some time, decelerating it over a greater period of time. I could be completely off-base but it's what popped into my head.
@@shibasurfing I'm not entirely sure it would. If anything, I think you might guess the blade design would be better.
Reducing the peak force / spreading out the impulse over a longer period of time would come from flex within the shape of the roll hoop. Both designs would be very stiff in the vertical direction but the blade would be more flexible as soon as there is a lateral component to the force thereby cushioning it a bit?
Then again, that is also a very double edged sword: flexibility in the bonded region may allow it to peel up from one edge - essentially only one edge of the join will take all of the force and it will tear away from that point.
That would be my hunch anyway. Of course its incredibly difficult to guess how stiff these structures are - especially since they'll have complicated internal geometries to maximise the strength while keeping weight low. That's what the FEM analysis will be used for
Surprised there was no mention of the similar accident Pedro Diniz had in 1999 without the halo where he got flipped at the Nurburgring and the roll hoop also failed. I honestly don’t think the Halo made as much of a difference as people assume having witnessed Pedro’s accident back in 1999 where its reasonable to say Pedro had a bigger impact once the roll hoop came off.
I just watched that other crash and my impression was that DIniz wasn't going as fast, but I'm not sure. It would be an interesting comparison if we had the telemetry data in detail.
Oh fuck Driver61 channel is hacked
Thanks for putting your face right over the picture of the track.
The tradition of Mercedes sending other cars to barrier in Silverstone
Reminds me of both the crash Diniz had at Nürburgring '99 and the controversy surrounding SNELL's testing of bike helmets
Just imagine if the car was on fire trapped in the barrier 😢 The FiA should be thinking about this and how to solve it
What's your point? Driver61 is speaking about the roll hoop, not the halo?? Do you want a lmp1 with the driver entirely covered?
@@filoudadidou bro i was just trying to bring awareness to this
Failure sounds like 'sheer' induced by tension. Load forces on roll structure transmitted to bonded area on monocoque. Layers of carbon fiber do not have much resin in between. When parts are formed, resin is introduced while part is in vacuum bag. Part then goes to autoclave where vacuum and heat cures resin. Many layers are supposed to become a single part, but weakness between layers remain. Lots of resin on top and bottom, not so much between layers. There can be many layers depending on requirements, so many little weaknesses hiding under surface.
fkn hackers
Great content as always! I don't think the FIA needs to depart from static testing versus just understanding all of the likely directions that the hoop could be loaded. It was an unusual event how the car rolled and I think the more likely culprit of the failure boils down to assumptions on the magnitude and direction of force (which is more of a kinematics problem). Teams already use FEA to design most if not all parts since it's been around for a long time.
Can anyone remember the last time a F1 car lost its roll hoop? The crash was really scary, they'll need stronger roll hoops and tests after this one
bruh did you even watch the video? clearly the hoop itself didnt fail
Something amusing/interesting to ponder: Some of the very earliest forms of pottery is taking clay, rolling it into long thin pieces, then layering them to form the shape of something akin to a vase. Contrast this with wheel turned stuff later on and you see the main difference is that the former is additive the latter is subtractive (if you will). The modern day 3D printed stuff like talked about in this video is really a high tech version of that technique which itself is only slightly younger than dirt.
Is it me or Gasly just cant resist sweezing between 2 cars ?
Even if he can, even if he is allowed, man... HOW MANY TIMES did it end up in DNF ?
Russell is obviously responsible here
I agree that gasly Needs to be more careful, but I feel like in this situation it wasn’t gasly’s fault. Russel should have seen him and if you watch the crash you can actually see gasly trying to brake out of the situation.
If we start policing drivers that way soon we'll be racing imaginary races in out minds.
Relying on the carbon fibre to hold such an important safety item is just DUMB !
The adhesive is only holding onto the outer layer of CF, and that later is relying on the inter-layer bonding strength.
The correct system of attachment should be bonding AND mechanical through bolts with anti-pull through pads.
This accident highlights the shortcomings of this design and will surely lead to improvements.
Great video.
now that is very interesting, and something that due to the materials involved, would be of great interest to airplane and rocket manufacturers.
great vid Scott and crew. B)
Another F1 engineer said it was the glue that failed since you can see parts of it still in place
0:33 ... It was the wrong place, wrong time thing.
Uhhhmmm.... This applies to EVERY accident. It's one of the definitions of an accident......
Roll Hoop: I'm still good guys!
Bonding Agent: We got this!
Monocock: Nope!
On the other hand, if we lose the halo and hoop completely, Piastri might have a seat.
Jesus Christ man hahahaaa
Great video, super informative and as always Scarbs makes it easy to understand. I'm guessing 3d-printing the entire car out of titanium is out of the question though.
Too heavy and not only would it be prohibitively expensive, it ould be significantly worse at absorbing energy from crashes
What would probably help is in addition to the 3-axis force test to do 1) a "torgue test" where you apply force from opposite sides on opposite ends and 2) a "rip test" where you apply force on the front top end in the upwards and rear direction.
This would properly test the bonds and carbon fibre in their weakest links.
If you wanna be extra fancy/safe you would do all 3 tests with static and dynamic forces.
2018 Monza: in FP2 Ericsson crashed the Alpha spectacularly. Although the roll hoop stayed intact there, because of the lighter cars and the not full fuel load.
It's worth to watch, you can see the full structure of the actual roll hoop, not only the drawing.
The fuel mass is negligible, usually about 90kg at the start of most races.
@@byanymeansnecessary9329 Fuel limit is 110 KG/race. And it's not negligable at all.
That roll hoop is detached because of the added weight.
@@gabormiklay9209 And Merc has won races using about 85 kg. Just because max fuel is 110kg doesn't mean they fill it to the brim for every race, and Silverstone is not a fuel heavy race. The load imparted on that roll hoop and the direction it was forced in would have caused it to fail even on empty tanks. In the 2018 Monza crash the roll hoop hit dirt, and not the track. Pay better attention buddy.
@@byanymeansnecessary9329 Still, at around 200 KPH (Zhou's speed before turning upside down) 90 KG is significant.
Also: roll hoops are designed to hit tarmac (because what else could and upside down racing car hit first).