Ford's inflatable seatbelts are designed to spread crash forces over five times more area of the body than conventional seatbelts. Used for rear-seat occupants, the inflatable belts help reduce pressure on the chest, and help control head and neck motion. (Source: Ford Motor Co.)
Very cool, Chuck. I've been lucky enough to never had seen an airbag actually deployed so it's really interesting to see all the various shapes and sizes and where they are hidden in the vehicle. The pinkish, odd shape airbag for preventing the driver and passenger from knocking heads is particularly interesting and odd-shaped. Any thoughts/intel on why it looks so freeform as opposed to most of the others which are more like big pillows?
Chuck, Great to see the images and actual visuals of how different airbags are designed to deploy. I am wondering how much the automakers are moving to more crash simulations versus actual crash testing. I'm sure they are still doing the latter but I thought they were moving in that direction. Thanks.
I understand that the airbags are inflated via a gas generator rather than compressed air. Can anyone confirim this? It also seems that the sensors have been vastly improved compared to earlier models.
I also recall from some years back that the cost of replacing the deployed airbags was quite high. This resulted in some cars being returned to service without air bags after an incident that triiggered the deployment but did not result in the complete loss of the vehicle.
It might be of interest to know how much it costs to replace the deployed airbags with new ones after an event.
It certainly seems that we ahve made enormous improvements in passenger safety.
I wonder what kind of cost/benefit analysis takes place during the design process about airbags versus extra metal. Presumably, a bigger car with a crumple zone in conjunction with air bags is more effective than either alone. The salient question is, in a small car with not much of a protective shell, how much safety (crash survivability) is added via chest, shoulder, waist etc. airbags. I don't know but would be curious.
I worked on airbag system crash sensors in the late 80's and early 90's. These were MEMS sensors and the engineering gulf between the automotive guys and the IC/sensor guys was amazing!
I am very happy to see the technology adopted so widely (even if by law) these days and knowing my 21 year old, who used to sleep in his stroller on Sunday while I was at work trying to make sense of sensor failures will always drive a safer car as a result!
Wow, that's an amazing amount of airbag types. Like Beth, I've never had a reason to seen an airbag operate so I don't know what they look like either. I think Alex's question is interesting. I'd guess that the number of airbags have increased at least because cars have gotten smaller, and also that they may have increased as more plastics and lighter metals are incorporated in car designs. Those lighter materials are, AFAIK, crash-optimized, but I wonder if there have been any tradeoffs: are they less crash-resistant psi than the metals they replace and are more airbags deployed as a result?
Good question about the size and shapes of the various bags, Beth. I would guess there is some size and bulk determination based on providing protection while still allowing emergency personnel to get to the person from the side. The ability to exit after a crash has to be a major consideration is slimming down the size for side bags.
Two reasons for the odd shape, Beth: First, it's not a full frontal bag and therefore doesn't need to catch the full width of a person. It's really just there for head protection, so it has to be tall. Second, it has to pop out of a seam in the seat, so it has to be skinny.
I can't give exact statistics on the effect of airbags in small cars, Alex, but I can take a stab at how airbags compare with other safety systems. In the early days of airbags, it was said that three-point seat belts would prevent about about 42% of fatalities and the use of airbags would bump that figure up to 47% (at the time, that would have come to about 2,000 fatalities per year prevented by airbags). More recent studies based on vehicles with multiple types of airbags have set the airbag number at 3,000 per year, which is still well below seat belts. By way of comparison, electronic stability control is estimated to cut the annual number of fatalities by 10,000 per year (based on a NHTSA study of vehicle crashes in Florida, Illinois, Maryland, Missouri and Utah between 1997 and 2003). And NHTSA predicts that vehicle-to-vehicle communications will save more about 24,000 per year. The bottom line is, airbags probably save fewer lives than the public expects.
Ann: I don't know the answer about small versus big cars, and whether the size of the crumple zone is generally taken into account when figuring out how many airbags to deploy. I can point to one isolated case, however. The GMC Acadia does not have kneebags because the large crumple zone in the front absorbs sufficient crash energy without the use of a kneebag. Regarding whether new structural materials are less crash-resistant: Most of the new structures are actually better, as I understand it. Big vehicles in the old days had more volume in front to absorb the energy, but they weren't designed for optimization of structural loads. Vehicle structures today absorb more energy. Finite element analysis, and understanding of load paths, has played a big role in the creating structures that absorb crash energy more effectively.
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