Hello all,

The module SIFs@Bends of CAESAR II, shows in the autput de in plane and the out of plane sif´s of the bend without a trunnion. Then it shows 5 differents Sif´s values for the bend "with" the trunnion.
I would like to know the difference between this SIF´s. I don´t have de Hankinson´s paper by the way.

Thanks and regards.

WHAT IS THE DIFFERENCE BETWEEN SIF IN PLANE AND SIF OUT PLANE?...

SIFs are actually fatigue correlation factors that compare the fatigue life of piping components (for example, tees and branch connections) to that of girth butt welds in straight pipe subjected to bending moments.

These bendings moments can be applied in the plane of the piping component (the piping component will rotate "in his" plane if you picture it as a two dimensional figure) or out of the plane of the piping component (the 2D picture of the component will rotate out of the plane). The figure 319.4.4A will be more useful for you to understand it than this post.

The piping component´s behavior under the out of plane and in the in plane moment is different so the SIF are different.

Regards

The additional 5 SIF values you refer to are from "Table 4" of <font color="#0000ff"> "STRESS INDICES FOR PIPING ELBOWS WITH TRUNNION ATTACHMENTS FOR MOMENT AND AXIAL LOADS"</font>, PVP VOL 129, 1987.

C_W - punching load
C_M - out of plane bending
C_L - in plane bending
C_T - torsion

The 5^th value C_max is just a summary value we put there to report the largest of the previous four values.

Boy!!!

It sure is a good thing that the B31 Codes are simplified!!! :rolleyes:

Thank you Mr. Richard for your response.

I finally found that publication. Now i have a new doubt. In the table 4 of this paper there are equations for the secundary stress indices C, but the module SIFs@BEND reports Stress intensification Factors (i). If 2i=CK, where did the value of the peak stress factor K came from?, it was assumed the value of 1?, why?

Thanks and Regards