4680 Update Structural Adhesive Tesla Model Y

ldjessee

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Definitely a structural material.
 

rr6013

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Well, it's resistant to damage ^-^

-Crissa
May be too resistant. Pink looks super-hard!

Tesla may have trouble ahead getting class1 Safety certified. Structural batterypack will transfer side-impact force into the passenger compartment. Loading forces into the floorsheet(neh, pan) exploding into soft tissue attached by bolts and belts. Bodies have to deflect force or absorb.
Pink teaches that the batterypack, as torndown, isn’t going to deflect, buckle or shear force. The only path out of the dilemma is exemption rating the vehice into a higher, exempt truck class.
To my eye, pink throws a re-engineering delay.
 

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May be too resistant. Pink looks super-hard!

Tesla may have trouble ahead getting class1 Safety certified. Structural batterypack will transfer side-impact force into the passenger compartment. Loading forces into the floorsheet(neh, pan) exploding into soft tissue attached by bolts and belts. Bodies have to deflect force or absorb.
Pink teaches that the batterypack, as torndown, isn’t going to deflect, buckle or shear force. The only path out of the dilemma is exemption rating the vehice into a higher, exempt truck class.
To my eye, pink throws a re-engineering delay.
The structural battery pack does not seem to be much different than the older Tesla packs when it comes to the sides, and Tesla gets great side crash test ratings without letting the test pole intrude into the cabin. The way Tesla reduces the force of side impacts is that there about 7" of metal and space between the side of the car (number taken from Model 3) and the battery case. Then there is more space in the side of the battery case to allow deformation before impinging on the battery cells (both in the old packs and the new structural ones). Tesla and all car makers use a mix of ultra high strength, high strength, and mild steel components in their crash structures to allow a certain amount of deformation in case of crash. The battery pack being structural does not mean that it is indestructible. Tesla puts crash test safety high on their list of priorities. Don't forget as well that the door, pillars, and roof also serve as structural members and are also designed to absorb impact for crash safety. And one can't forget as well that Teslas have side impact curtain and hip air bags that help as well.
 


rr6013

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Then there is more space in the side of the battery case to allow deformation before impinging on the battery cells (both in the old packs and the new structural ones).
Noticed side gutters were ample in early 4680 schematics. So that empty area is Safety Zone by design, not extra battery space. You’ve provided very helpful information. Hope Cybertruck joins Tesla’s stellar list of Top Five Best Safety Rated.

Tesla chose such a non-compliant foam to get the entirety of the batteries to act as one rigid block structurally. That’ll counter torsional flexure within a hollow metal boxed batterypack. So exoskeleton flex is minimized. Longitudinal deformation should be stiffest thanks to foam to the benefit of the weakest point of the exoskeleton(at floorpan). OK, starting to make better case for rigid foam.

Crumple deformation may be a reason why the Cybertruck has such generous headroom. If the floorpan is designed to crush, crumple and fold at its perimeter, occupants will be deflected up from side impact collision. Critically, up and away from forces being transmitted into the batterypack floorpan. IDK, anything about floorpans only in a Mercedes side impact that came all the way into midline of car.

Seat brackets, seatbelt anchors and interior furniture attach to the batterypack topsheet. Pink foam is structurally bound to that batterypack metal topsheet( i.e.floorpan). So occupants are attached. And the pink foam is completely isolated from the bottom metal of the bellypan. Which translates to freedom to deform - a good thing! The one saving grace from the Mercedes impact was occupants were thrown up above the impact with only a broken pelvis.

7” inches of safety margin is only so much comfort(~35mph) when an impact intrudes beyond that into the occupant space. B-pillars are a great support for the crash beam hidden inside doors. Hip airbags save pelvic impact. Tesla Safety ratings are industry best. Structural floorpans are a whole new element as is the exoskeleton.

Thanks again for your helpful information how Tesla designs for safety first. So much Cybertruck is new. Its hard to appreciate Tesla’s work getting it production ready. It amazes.
 

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Don't forget that occupant safety is primarily about reducing passenger deceleration g-forces and making sure there is no to little cabin intrusion.

So you want a not compressible safety cabin (structural pack) so passengers don't get crushed, which then means you need to find a solution to reduce deceleration forces.

The very short Smart car achieved this by having a rigid external shell that was impacted, but the internal volume and space of the cabin was used to the max to gradually decelerate occupants with multi stage airbags. The same can be done for side impact protection on the CT, on top of any structural crush zones.
 

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Don't forget that occupant safety is primarily about reducing passenger deceleration g-forces and making sure there is no to little cabin intrusion.

Exactly. If the crash gets to the rigid cells and foam you are already intruding into the passenger compartment in a very dangerous way.
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