A engineer at Volvo has come up with a "hybrid stainless steel assembly"..it's a sandwich of 2 quite thin steel sheets bonded to a core of steel fibres about 20 microns thick. The advantage is in crash tests it absorbed about 50 to 60% more energy than sheet steel. So either stronger, or they figure cars built using HSSA could be 50 to 70% lighter. Pretty technogeeky and maybe minimal application for bikes, but I thought something stronger than steel and lighter than aluminum was cool. Be good news for the SUV crowd anyway For anyone interested, here's the article in PDF, it's from a magazine I design for a mining lobby group:
Well Huey everyone knows this one hybrid stainless steel assembly "glue" at 20 microns that is real thin
Maybe it's just red locktite? I wonder if they could zap the two plates and sinter the fibers?!?!? Probably warp the plates.
HotRoll the "sandwich" and have a solid steel core lamination. The hotroll "welds" (hot as in electricity) the two sheets together, controls thickness, and prevents heat distortion. Then the sheet is run through a sort of heat treat (depending on what it will be used for) process. Final product is some strong stuff.
Anyone catch the show playing on cable (TLC, I think) about the history of race car design? Concentrates mostly on the Indy series and open wheel car design. Describes how they first tried to make the cars safer by making them stronger, but learned that just killed drivers. Most interesting was the mechanical engineer who says that from what they've learned the government standards for crash testing for consumer vehicles are all wrong.
The process is called flocking!! they use epoxy and an elctromaganet by varing the feild the fibers stand on end and repel one another the the other sheet is epoxied and pressed on top of the othe furry sheet pressed and baked to give a 1.4 mm thick sandwich
Flocking??!! Awe Hell.....I just "Thunk" up that process in my head!!! Sucks being an unemployed Engineer!!!
IMO the whole idea of government crash standards is wrong. If the damned things weren't so crashworthy then the public wouldn't be so anxious to run over each other. You never say a guy in a VW beetle or a Yugo looking for someone to bully with his vehicle or not paying attention at an intersection.
I agree Doc! What about what Frank was saying? The days of big ol METAL dash, METAL buttons, METAL steering wheel! After the accident just hose out the interior and put it up for sale!
I'm guessing they learned sort of what you described in your first paragraph? ie cars should better "accordion" and self-destruct to absorb more force? I am amazed sometimes when I see an F1 car absolutely disintegrate ...and the driver walks away. Not to start any flames but that was what I had read as a major flaw in any truck-based (rigid framed) vehicle.. which is why some people say buses should not have seat belts. But that doesn't make sense since SUVs have truck frames ..and seat belts. Anyway luckily for them there are lots of nice soft cars they can use to slow down
That's pretty much it. They've gone through an iterative process whereby they've changed their ideas quite a few times as they learn more. They found out that although the cars were going over 200 MPH that the relative impact speed was only about 50 MPH. How fast you slow down is what matters, not how fast you are going when you crash. Thus the designs to release energy by coming apart. The latest problem they have is now that with the stronger noses designed to eliminate driver foot injury they've designed very effective "missles" that penetrate other cars when they hit them. So they are working on ways to increase the cross section of the noses so they protect the driver's legs, stay aerodynamic, and don't penetrate other cars so easily.
Capsule is strong as possible and everything else is mounted to shear plates. Energy is absorbed by the deformation of the plates and everything mounted to them and not transferred through the pieces and into the tub. Designers also finally got it together and began requiring deformable structures around the drivers helmet and head/neck restraints. Of course, none of that helps if your steering wheel comes apart in your hands (Ayrton Senna).
The picture I wanted to use in the article (it was too low resolution) was some sort of crush test at MIT.. the HSSA stuff had about 10 or more "accordion" folds in it. I think the key word is it "absorbed" 50 to 60% more energy, rather than simply being stronger. Not that I'm an expert, hopefully if it works its not 10 years off.
When the engines detach from the chasis it lowers the momentum of the remain piece with the driver attached.
They are at the point where they are designing the transmission cases to deform on a rear end impact so that the energy isn't transferred forward to the cockpit.
That's all true but it is the relatively smaller bits that play a big role. Think of the kind of impact required to shear an engine/transaxle. While you design for them to take a big hit and hold on to it rather than transfering, you are still talking about a huge impact and one that is difficult to "control". On the other hand, relatively smaller pieces like radiators, suspension pieces, wheels, wings, etc. can be designed to absorb the majority of an impact by shearing away and deforming in a minor or medium impact. Relatively minor or medium impacts are the ones where you can have the largest influence on driver safety, and these were the types of crashes where people were getting injured unnecessarily.
