Mean stress effects on fatigue, ASME section III NB3200

[hath11]

Hi,

For Level A service limit (NB-3222 in Section III) a fatigue evaluation based on Sa is made. The stress range (Pl+Pb+Pe+Q) is also checked against the 3Sm limit in order to prevent ratcheting. My question regards the mean stress effects. Are they not considered?

Best Regards
Thomas Haraldsson

 

[zjliang]

Yes, the mean stress has been considered in the fatigue curves of different materials (See the notes). So, no need to shift the curve or play with the Goodman chart any more.

Thx.