Hi, I was thinking about repair of the car in case of a fender bender. The monocoque is stated to be a honeycomb core based composite structure. While this lends itself to a rigid light weight structure, it will likely delaminate (disbond of the skin from core) or puncture if impacted. If someone backs into it or it is hit by something bouncing down the road there could be issues. Very few automotive focused shops have any kind of composite repair capabilities. One might get away with drilling out a damaged area and pumping the core full of resin. Minor repairs might be made with local vacuum banging and heat blankets, but good structural repair would require an autoclave and appropriate mold tools. Going into the autoclave would also mean stripping the monocoque down.
So, if a person got into a significant enough accident I wonder if the electrical and mechanicals could be moved to another shell? I recognize that the Aptera is fairly affordable, so it might be a write off if you get hit. Composites just behave differently than metallics when they are damaged. Fracturing rather than yielding and that kind of stuff.
I’m also curious if the manual system will have good non destructive testing instructions in it. Obvious delam can be found by a simple coin tap test, but I would expect some standards and inspection intervals for key load paths.
A bit of nerdy background, I ran the composite engineers for a major airline and aircraft maintenance repair organization (MRO) for about 10 years. We had large composite structures used in engine cowls, various fairings and flight controls forever. When we got 777s with their composite floor beams things got a bit more serious and with the A350 (composite fuselage and wings) and A220s (composite wings) joining the fleet things got really serious. Repair and inspection of highly loaded composites is a tricky thing. I love the idea of a composite car, but like EV charging, there is a whole infrastructure that needs to be developed to work on them.
Hitting the car with a blunt hammer is all well and good, now do a pointed one pound rock at 30 mph.
Don’t know anything about this but Chris’s “start“on whatever is settled on for the Aptera... comes from the “bag and form”pricoss he used on his Elite boat manufacturing
We shall see
@michael.rennick
It's good to know how something like this is repaired, we will need this knowledge more often when the front and rear wheel covers are damaged by potholes and rocks. I will remember your username 😉
Yes, I’m not saying that bonded structures aren’t the way to go, it’s just there is a whole set of different ideas that need to be explored in the long term to ensure that they are viable. Metal constructed cars have 120 years + of learning behind them. Carbon bonded structures in aviation have about 60 years, but they have rarely been out of environments where specialized tools, processes and trained people were near by. It will be interesting to see what happens when when this tech is in the hands of the masses.
Here is what is going on in a few sites in California. It may not be the exact composite combination, but here is how honeycomb carbon fiber is laid up in the sophisticated America's Cup racers. It is usually a mold which is vacuum bagged to press the composite down without air pockets. Very different in how we make surfboards.
https://www.youtube.com/watch?v=u5qSesZFRG0
You have to remember that the construction techniques come from the boat building industry, not aircraft. Autoclaves are not used.
I work in the marine industry and know something about this. Most of your comments just do not apply to the vacuum bag and UV curing methods of construction. Many collisions that would result in crumpled metal with conventional metal parts will be a simple scuff repair on the Aptera. Materials for more extensive repairs are available at any West Marine.
Nice discussion. For those of you who are not aware, both the BMW i8 and i3 have composite life cabins of carbon fiber reinforced plastic. Except for fasteners and some electrical components the entire cars are made of aluminum subframe forgings and "plastic". When a structural composite area is wrecked, that section is cut out and a replacement section bonded back in. The plastic body skins are then attached. There are not too many shops who are knowledgeable on these repairs.
For those of you engineering nerds out there, here is a video of the Leipzig plant that builds only BMW electric "i" cars. The plant itself is amazing in that it is completely powered by solar and wind power. You will also see how BMW gets sub-millimeter fitment on the car chassis and body assembly. Unlike Aptera who basically will be assembling parts built from outside vendors, BMW makes their own batteries, motors, and electronics, so I am not saying that this is what Aptera should be doing. I like Aptera's concept. The BMW "i" cars have not been terribly successful in the US, mostly because of their prices. It is an oxymoronic description of a "luxury sub-compact". The i3 is designed as a city car, and not a long range traveler. Please remember that this model started in 2013 and is still in production. It is still quite popular in Europe. But you will see that like Aptera, it is an entirely different concept than a standard production internal combustion engine car.
If enough of you enjoy this (I find it quite relaxing), I will give you some videos on the actual battery production which is done inhouse. I think you will see the similarities to the Aptera which is just 9 years later. Enjoy.
@OceanDragon
Thanks for the link, please post more.
What I do not understand, orange color at the robots normally stands for KUKA not for ABB (white).
Thanks Bruce. I will have to do some research to better understand how the boating industry uses composites. I was going off their comments in the Tech section of the site stating that structures were based off of aviation and motor sports processes. That led me to common prepreg and wet layup carbon structures. Some of the videos that I’ve seen seem to indicate a traditional light weight hex core with what looks like bonded skins. The types of resin they are using would make all the difference in the curing process.
I’m going to stash this here for reading later Reading for me.
https://res.mdpi.com/d_attachment/jmse/jmse-08-00026/article_deploy/jmse-08-00026.pdf
I understand that cooling channels are integrated into the body part. Could be really tricky to repair those sections? Are the 4 body parts bolted or riveted and can be easily exchanged??
Maybe I'll wrap the front of my Aptera with kevlar... It would be a good idea if Aptera Motors had an option to send your car back for a factory refit if damaged or in need of updating after, say, ten years.
Living n Australia 500km away from the next capital city I like to see the right to repair applied to body issues well. Like with boats and aeroplanes it would be good to have clear and simple repair procedures and repair kits available for purchase. I currently own a Tesla and their current policies on this matter makes it the last Tesla for me....great car though.
@Rheingold