edrush
Materials
- May 14, 2003
- 66
Shigley's Mechanical Engineering Design (5th, 9th and 10th editions) say "set removal should not be used when springs are subject to fatigue". It provides no explanation.
I am working on a helical compression spring and this confuses me. The residual stresses created by presetting should reduce the peak stress for both static and dynamic conditions. So why is this not recommended for fatigue service? Possibly this is a size issue because a much larger volume of material (the entire plastic zone) will be under high stress? I realize that presetting will not change the fatigue stress range, so based on some fatigue failure criteria (maybe all?) there is no benefit, but I not seeing why presetting would be detrimental.
Any insight others have on this issue will be appreciated.
I am working on a helical compression spring and this confuses me. The residual stresses created by presetting should reduce the peak stress for both static and dynamic conditions. So why is this not recommended for fatigue service? Possibly this is a size issue because a much larger volume of material (the entire plastic zone) will be under high stress? I realize that presetting will not change the fatigue stress range, so based on some fatigue failure criteria (maybe all?) there is no benefit, but I not seeing why presetting would be detrimental.
Any insight others have on this issue will be appreciated.
