Applies To
Product(s):	AutoPIPE
Version(s):	ALL;
Environment:	N/A
Area:	Calculation
Original Author:	Bentley Technical Support Group
Date Logged & Current Version	Nov. 2016 10.01.00.09

Problem:

When calculating the SIF for a bend with:

Nominal pipe size = 8.00 inch

Wall Thickness = .127

Bend radius = short (8.00 in)

Qual Stree = 40

Biaxial Type = 100% hand lay

SIF = 2.5

However, if the bend radius = Long (12.00 in), SIF is still the same, why?

Solution:

Per code, ISO 14692-3:2002(E), section "D.2.2.3 Stress intensification factor (Sf )":

An upper limit, based on experience, is placed on all four Sf . No Sf shall be greater than 2.5.

Therefore SIF range is:

1.0 <= SIF <= 2.5.

Calculation of aforementioned bend exceed the SIF range set by the code, thus a 2.50 value was used instead.

Note: Remember that one can override the SIFs by Inserting a User SIF from the Insert>Xtra Data menu.