Calculating Stress Range For Fatigue Exemption
Calculating Stress Range For Fatigue Exemption
(OP)
Dear all
Based on ASME Sec.VIII Div-2,I have performed calculations for exemption of a vessel from detail fatigue calculations. In my calculations Method A screening criterion could not exempt the vessel however, by applying method B the vessel was exempted from fatigue calculations.
I sent the calculation document to be reviewed then the reviewer of the document has rejected the document for the following reason:
"Fatigue of pressure parts is subject to stress range, stress range should be calculated before starting screening method"
Furthermore, he continues to ask for development of a histogram via cycle counting method of rainflow. He also wants me to calculate the stresses due to combined effects of temperature gradient and mechanical loads.
I think this comment is totally wrong since if I am supposed to do a detailed stress analysis and then apply rainflow or other methods of cycle counting in advance, then it would not be called an exemption method.
Can you please help me understand what the comments mean?
Warm Regards
Based on ASME Sec.VIII Div-2,I have performed calculations for exemption of a vessel from detail fatigue calculations. In my calculations Method A screening criterion could not exempt the vessel however, by applying method B the vessel was exempted from fatigue calculations.
I sent the calculation document to be reviewed then the reviewer of the document has rejected the document for the following reason:
"Fatigue of pressure parts is subject to stress range, stress range should be calculated before starting screening method"
Furthermore, he continues to ask for development of a histogram via cycle counting method of rainflow. He also wants me to calculate the stresses due to combined effects of temperature gradient and mechanical loads.
I think this comment is totally wrong since if I am supposed to do a detailed stress analysis and then apply rainflow or other methods of cycle counting in advance, then it would not be called an exemption method.
Can you please help me understand what the comments mean?
Warm Regards





RE: Calculating Stress Range For Fatigue Exemption
RE: Calculating Stress Range For Fatigue Exemption
Now I feel much safer. One more thing about his comments is that he claims that if you want to exempt an equipment from detailed fatigue calculations you need to exempt it from both methods A and B. I do not know how to deal with this guy.
Warm Regards.
RE: Calculating Stress Range For Fatigue Exemption
RE: Calculating Stress Range For Fatigue Exemption
RE: Calculating Stress Range For Fatigue Exemption
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calculating Stress Range For Fatigue Exemption
As far as the thread is concerned I do not see anywhere it states that the "reviewer" is the Client - It could be a third party!!
RE: Calculating Stress Range For Fatigue Exemption
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calculating Stress Range For Fatigue Exemption
Warm Regards
RE: Calculating Stress Range For Fatigue Exemption
It is frustrating giving someone outside you company a free education. Especially as they always resist and rarely show appreciation for the education that you have provided them.
RE: Calculating Stress Range For Fatigue Exemption