SIF VS Y connection in a B31.3 piping system

[hcjulien]

Hi,

To be able to realize a complete stress analysis, I'm searching for a way to determine the ''i'' factor (Stress Intensificator Factor) of an unreinforced fabricated ''Y'' connection in a B31.3 piping system. Can you help me out?

Thanks in advance,

Hcjulien

 

[DSB123]

hcjulien,
Conduct a FEA of the Y piece and calculate the SIF's from the results.

 

[hcjulien]

Thanks DSB123,

No problem to create a FEA analysis, but how can I still find the SIF?

What I was thinking to do is finding the Von Mises stress ratio : stress at the Y connection (at the weld) divided by the stress in a straight pipe (having the same diameter as the the smallest diameter in the Y connection). My ratio will be my SIF. The same design pressure with the same created Moment will be used for both stress analysis.

What do you think?

regards,

hcjulien

 

[ZippyDDoodah]

hcjulien asks a good question - Are there traditional, industry accepted methods to translate FEA results to an SIF? If so, where do we find them?

I understood SIFs to be based on fatigue.