Ansys Fatigue in Workbench

[Stum3]

Hi all can anyone help

when doing a fatigue safety factor in Ansys WB 13

it would seem anything above 1x106 cycles doesnt change

the fatigue safey factor.

ie i have just set up the same analysis with 1x109 cycles

and 1x106 cycles and the SF doesnt change it only changes

when you get below 1x106 cycles a little confusing

can anyone help

Thanks

Stu

 

[TERIO]

This is not really a question about ANSYS. You should read up on fatigue before dong a fatigue analysis. Specific to your question, you should read about endurance limits, then determine if they are applicable to your specific material.

 

[Stum3]

Thanks

but it is about ansys, the material is carbon steel
and i have found my answer


"In a constant amplitude analysis, if the alternating stress is lower than the lowest alternating stress defined in the S-N curve, the life at that point will be used."

Hence the stresses in my analysis were very low but it does give
confusing results if you dont know the above

Stu