Would people here be interested in aftermarket control arms for the $500-$900 range?
03-19-2007, 10:11 PM
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Hi Daniel,
Just in case you weren’t already aware, a word of caution...
Any of the hi-carbon steels (like the one you're looking at using) have a tendency to form hard spots when welded and are typically stress relieved in order to keep the material homogenous throughout under high stress applications.
If your stresses get high enough you can run into problems with cyclical fatigue and cracking and the arms can let go around the welds without warning. SolidWork's Cosmos has no provision for this mode of failure and everything will look wonderful on the monitor when you run the static analysis.
I've personally seen 4140 weldments break apart from fatigue with safety factors as high as 3:1 on the material's yield strength with only a 100,000 cycles on them (surface finish issues). Fatigue around welds is always a problem with weldments and you will need to put hefty safety factors on them to keep yourself out of trouble.
Also, not preheating the part before welding (growing the part) can sometimes be enough to induce adequate stress in the joint to cause it to fail if the two pieces you are welding don't heat up exactly the same amount. By the time you finish a bead of weld the material may have already grown several thousanths of an inch from where you started the weld cold. As the bead cools down the joint can easily reach yield. This would only be a problem if you were not stress relieving the part after welding.
Good Luck with it!
Just in case you weren’t already aware, a word of caution...
Any of the hi-carbon steels (like the one you're looking at using) have a tendency to form hard spots when welded and are typically stress relieved in order to keep the material homogenous throughout under high stress applications.
If your stresses get high enough you can run into problems with cyclical fatigue and cracking and the arms can let go around the welds without warning. SolidWork's Cosmos has no provision for this mode of failure and everything will look wonderful on the monitor when you run the static analysis.
I've personally seen 4140 weldments break apart from fatigue with safety factors as high as 3:1 on the material's yield strength with only a 100,000 cycles on them (surface finish issues). Fatigue around welds is always a problem with weldments and you will need to put hefty safety factors on them to keep yourself out of trouble.
Also, not preheating the part before welding (growing the part) can sometimes be enough to induce adequate stress in the joint to cause it to fail if the two pieces you are welding don't heat up exactly the same amount. By the time you finish a bead of weld the material may have already grown several thousanths of an inch from where you started the weld cold. As the bead cools down the joint can easily reach yield. This would only be a problem if you were not stress relieving the part after welding.
Good Luck with it!
Last edited by 82-928/89-S2; 03-19-2007 at 10:30 PM.
