Fatigue analysis - ASME III NB-3653.2 Eq. 11

[smk4]

Hey,

Does anybody know what kind of methods are used in the piping fatigue anaysis industry to solve the pairs of load sets needed for the ASME III NB-3653.2 Eq. 11 (peak stress calculation)? (Does anybody use the rainflow method?)

Also, can someone give me the contact information for the following programs:
NuPipe, ME101, Superpipe, KWU-ROHR

Thanks for any help!

 

[davefitz]

The rainflow cycle counting algorithm is used in the european fatigue codes ( PED). It was first used in the 1970's in Japan to analyze bridge fatigue under earthquake loadings . It was finally recognized in europe in the 1990's and now is the primary means of computing fatigue damage under complex loading history

 

[davefitz]

Refer to EN-13445 ( EU equivalent to ASME sect VIII div 2) and EN-12952 ( EU equivalent to ASME sect I but with fatigue added) for the newer european code fatigue methods.

 

[LSThill]

sarah4 (Mechanical)

Regards to the Piping Stress Analysis "ME101" contact BECHTEL

 

[zjliang]

Done a lot of fatigue analyses for pressure vessels and piping by using ANSYS. But I think the basic theory should be the same. The rainflow counting algorithm has been built in most business softwares, so I do not think you need to bother figuring it out by yourself.

 

[NormPeterson]

I'm pretty sure that NUPIPE uses a rather brute force approach and computes for every possible pair. Then it sorts the pairs and starts counting cycles, removing events from further consideration as their cycles are used up. Eventually, you either run out of events/cycles (using a dummy thermal case for thermal cycle exhaust) or drop below the point at which the fatigue contribution need be considered.

Shaw Stone & Webster is one user of NUPIPE, though I think its version differs slightly from the original (Quadrex?). Unfortunately, I don't know who you would contact.


Norm