Israelkk,
Thanks for the calculations and tips on residual stress.
I will try to reduce the residual stresses somewhat more. This might give me the small improvement required to meet the lifetime of 100 000 cycles.
I have tried to verify your calculations: not bad without a specified drawing...
Spring constant of all springs is identical, at least not significantly different.
Of course there is difference in eye-eye distance due to manufacturing tolerances. But both springs with small and with large distances crack.
Thank you all for your thoughtful answers.
Let me try to answer the questions in all the posts above:
Production tools are checked on burrs, sharp edges, etc. Same tools are used for the second spring, but with slightly different setup.
Spring are checked on burrs, sharp edges before...
Thanks.
Too bad the attachments do not work, I will try to upload the file again, but probably with the same result.
You are right in your reaction. If I review the Goodman or Soderberg curves, fatigue life is more related to alternating stress than to mean stress.
But still, here are the...
In one of my companies products, a steel leaf spring operates two plastic parts. The spring sometimes brakes before its required life. See attached photo's.
Description:
size between eyes is 15.0mm after production. After assembly, the size is 16.4mm. In one cycle, the spring is strained to...
