standard stresses on suspension parts?
standard stresses on suspension parts?
(OP)
I have designed a suspension in catia which I would like to stress test. As I am not an automotive engineer, is there some standard stress that you put on certain places of the suspension in order to determine that it is capable. If so, where would I find these numbers?





RE: standard stresses on suspension parts?
Dan
Owner
http://www.Hi-TecDesigns.com
RE: standard stresses on suspension parts?
RE: standard stresses on suspension parts?
The highest stresses will be shock loads from when you hit something solid, but what is reasonable ?
A race car may never be expected to hit a curb or gutter, and if they do, it is usually at frightening speed.
Would it be reasonable to expect a vehicle to get completely airborne and then land heavily on one wheel?
Normal fatigue limits are one thing, but one time destructive overloads are something rather different.
RE: standard stresses on suspension parts?
RE: standard stresses on suspension parts?
Dan
Owner
http://www.Hi-TecDesigns.com
RE: standard stresses on suspension parts?
Of course a bit of excess weight might not be of concern.
Regards
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RE: standard stresses on suspension parts?
Dan - that is a reasonable approach, but it is twice as much modelling work. 3-2-1 , or as I have suggested, 5-4-2, is a pretty good approach, designs based on that rarely need significant re-designs. Make sure your billet aluminium has a guaranteed elongation at failure of at least 7% right through the billet.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: standard stresses on suspension parts?
RE: standard stresses on suspension parts?
Just wondering how difficult it would be for me to re-engineer some components on my car. I have a decent mechanical background (degrees are in EE, not ME), but very little when it comes to computer simulation of part stresses, etc. My idea would be scan the part in (either by multiple caliper measurements, cheap access to a laser scanner, etc.), enter appropriate data (such as materials, load points, etc.), and get typical/max stress values. Once I have the worst-case for that material, begin redesigning a piece out of aluminum that meets (or exceeds) those max specs, but is obviously lighter.
This isn't a money making idea, simply something I would do in my spare time to play with my car (though selling a few extra pieces to pay for mill time wouldn't be a bad idea). As always, I just love learning new stuff.
Dan
Owner
http://www.Hi-TecDesigns.com
RE: standard stresses on suspension parts?
However, FEA has many pitfalls, and for the interested amateur, even if you avoid the modelling problems, the biggest difficulty is getting hold of good correlation data.
As an example, two of us have just run a correlation exercise on a ladder frame chassis. Building the FEA model probably took 20 hours (off the top of my head). Building the test rig and getting the results sorted out for the correlation took two or three times as long. I'm very glad we did it though, my FEA was nothing like as accurate as I'd hoped it would be. Once I knew where the problems were it was very easy to improve the accuracy. Now it is a reliable basis for further modifications.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: standard stresses on suspension parts?
Amen Brother
RE: standard stresses on suspension parts?
Check out MTS Corporation's "SWIFT" Wheel Force Transducer. Their brochure lists the load capacities for vertical, lateral and longitudinal forces.
RE: standard stresses on suspension parts?
Dan
Owner
http://www.Hi-TecDesigns.com
RE: standard stresses on suspension parts?
RE: standard stresses on suspension parts?
For lateral and longitudinal loads most data is taken with strain gaged components and not with accelerations. The load paths for these directions are stiffer than the vertical load path. Again, pot holes and curb strikes cause the largest loads. A big part of the lateral load is from reacting the moment created by the accelerating vertical mass striking the jounce bumper. We used about 4000 lbs for lateral inputs and 6000 lbs for longitudinal inputs.
You would not want to design your parts for millions of pot hole strikes. Maybe 100's.
RE: standard stresses on suspension parts?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: standard stresses on suspension parts?
I use a simulator that has 18Kip vertical (after the 2.5:1 bellcrank), 11Kip Fore/Aft, and 7.8Kip Lateral capacity and wish it had more capacity, 5 Kip would barely tickle a suspension vertically and still get the required velocities.