Your question is incorrect: Since the bar took a tweak, it is NOT
elastic deformation. Look at a standard stress/strain curve to failure
for a mild steel: elastic region (straingt line upwards) on the left,
then inelastic wobbly line to failure on the right. You have used up
some of the available space between elastic and failure. How much is
hard to judge. If it took a substantial tweak, I don't want to drive it
at speed.




Brian wrote:
I have an anti-roll bar from a Formula Ford race car that has suffered a
bit, and has a twist. It's obviously not up to it's original use in a mild
steel spec, but I modified the suspension design somewhat and it will not
see nearly as much potential twist in use. What I wonder is can I simply
twist it back into alignment, either hot or cold, and have it perform pretty
much as it did before it got twisted and then untwisted? I can't see why
not, but I have cumulative fatigue factors in mind that I don't know about.

My thought is to replace the ARB with a 4130 heat treated version , but I
want to drive the car first to see if the bar rate is close to right. Then,
I'll make up one with the correct rate in the correct material.

Thanks, Brian