Cyclic plasticity for fatigue evaluation

[gurmeet2003]

I have an application for fatigue evaluation where the stress goes above yield. I have briefly surveyed the literature both FEA and fatigue. It appears that I need to specify cyclic stress-strain properties. The materials are AISI 4140 (UTS 150000 psi) and steel UTS 80000 psi. If any one could throw some light on these material properties and where I can get them I will be highly obliged.

Thanks,

Gurmeet

 

[NickE]

Do you mean that the part yields on every stress cycle?

I don't think that standard fatigue would apply.

Nick
I love materials science!

 

[gurmeet2003]

Nick,

Yes the part does yield in every cycle for a number of cycles and then it stablizes due to strain hardening. The subject is called cyclic plasticity.

Gurmeet

 

[TVP]

Gurmeet,

SAE J1099 has some data on LCF properties of 4140, 4142, and 4340, but not necessarily at the exact value of UTS = 150,000 psi. There is also data on low carbon sheet steels with UTS around 80,000 psi. It is a relative bargain at $47.20 for members, or $59.00 for non-members. You can obtain it directly by download from SAE by using the following link:

http://www.sae.org/technical/standards/J1099_200208

 

[gurmeet2003]

TVP,
Thanks, I am getting this standard.

Gurmeet