Composite Flexures
Composite Flexures
(OP)
Hi,
I'm as you can tell new to this forum. I would like to know more about composite flexures and their uses + designs as part of automotive suspension.
Can anyone give me an idea of how they work, design aspects, analysis, etc.? Or any links to articles or resources (online or print) would be great as well.
I have tried google and maybe these designs are too new? I can't find much on it.
TIA
I'm as you can tell new to this forum. I would like to know more about composite flexures and their uses + designs as part of automotive suspension.
Can anyone give me an idea of how they work, design aspects, analysis, etc.? Or any links to articles or resources (online or print) would be great as well.
I have tried google and maybe these designs are too new? I can't find much on it.
TIA





RE: Composite Flexures
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Composite Flexures
There are common suspension springs on production cars, usually transverse, that are often referred to as being composite. But nearly all are fiberglass.
RE: Composite Flexures
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Composite Flexures
Many GM cars use of have used transverse fiberglass leaf springs at one time or another, and for several years.
RE: Composite Flexures
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Composite Flexures
http://20car.com/specials/spec26.htm
Sorry, I assumed the OP was after the arm to body mounts, which are small beams made of something or other that often last for a whole race.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Composite Flexures
Corvettes not only still have them in the rear, but they've been using them in the front suspension for a few years. Chevrolet still calls them "composite". I think Ferrari, Volvo and others use them too.
ht
I'm still not sure what the OP was referring to.
RE: Composite Flexures
I'm not sure how that will help though.
RE: Composite Flexures
RE: Composite Flexures
Composite flexures are very uncommon for SLA suspensions. My FSAE team designed and built them into the a-arms on all four corners of our 2006 car. To our knowledge we are the only people to ever do this. The flexures were carbon fiber along with the entire a-arm. We used carbon as opposed to titanium because we are required to design for 2" of total wheel travel. Titanium can't deal with this type of strain to my knowledge.
Anyways, to answer your question. Design issues are as follows:
1. Stiffness- reduce it so that it does not add additional stiffness to your suspension.
2. Buckling- main failure mode of the flexure aka how it will break in actual use.
3. Compressive failure of skin due to high flex angles.
4. Fatigue- theoretically composites have infinite fatigue however we know that this isn't always the case in practice due to inconsistencies, scratches, cracks, etc.
Aaron Cassebeer
2007 Lehigh FSAE Team Leader
RE: Composite Flexures
RE: Composite Flexures
Jordan Grand Prix did use spring steel flexures in 1993 I believe.
Ben
RE: Composite Flexures
The F1 Ferrari very recently used a composite lower control arm that was one piece from wheel to wheel, and was the flexure. It may still be under their current car. However, it did have a titanium spar inside of it.
RE: Composite Flexures
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.