Fatigue Assesment in the ASME BPVC

[Civilfatigue]

Hello,

I would like to ask for help in the fatigue assesment by the ASME BPVC.
I'm trying to make a fatigue assesment with ANSYS, wich uses the ASME BPVC code for fatigue calculations, and i have some doubts about the code.


1- Which is the stress amplitude i must calculate to use in the S-N curves? Is the Sa (stress amplitude,where: Sa= (Smáx-Smín)/2)?
Or is the Stress intensity (maximum alternating shear stress, based on Tresca's criterion)?

2- Which stress parameter is considered in the SN curves of ASME BPVC? Is the Sa versus N, or is the "Stress Intensity" versus N?
(N is the number of cycles to failure).

I will be very grateful for any help in this.

 

[TGS4]

All of your questions are answered in the BPV Code itself. Read it and feel free to come back here if you have specific questions.