HELLO ALL
I HAVE SOME DOUBTS. WILL SOMEONE KINDLY CLARIFY?
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I have run a program and the foll. is part of the output under heading
LOAD CASES - SUSTAINED ; REPORT OPTIONS - STRESSES
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*** CODE STRESS CHECK PASSED
PIPING CODE B31.1 -1998, September 15, 2000 Addendum

HIGHEST STRESSES: ( KPa)
CODE STRESS % : 86.21 @ NODE 330
STRESS 50954.6 ALLOWABLE 59101.9
BENDING STRESS : 65905.7 @ NODE 40
TORSIONAL STRESS : 4273.9 @ NODE 330
AXIAL STRESS : 4998.8 @ NODE 20
HOOP STRESS : 6230.5 @ NODE 15
3D MAXIMUM INTENSITY : 67665.1 @ NODE 40

However, on checking the stresses corresponding to node 330, in the detailed listing below, the following is the output data for node 330:

Node Bending stress Torsn. strs SIF's Code stress Allowbl. stres %
320 5681 1710 1.0/1.0 9680 59102 16
330 4636 -1710 2.756/2.756 10927 59102 18


330 5775 -1996 2.756/2.756 12368 59102 21
340 8924 1996 1.0/1.0 12825 59102 22
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My doubts are the following :
1. THE HEADING SAYS THAT CODE STRESS % IS 86.21 AT NODE 330 BUT THE DETAILS IN THE LISTING SHOW THE CODE STRESS AT 330 IS ONLY 18% OF ALLOWABLE STRESS. WHY THE DIFFERENCE ?
ALSO THE 'TORSIONAL STRESS : 4273.9 @ NODE 330' IN THE HEADER. BUT THE DETAILED LISTING SHOWS
THIS VALUE AS 1996. WHY?

2. WHY ARE THE STRESS VALUES FOR THE SAME NODE DIFFERENT FOR ADJACENT ELEMENTS EG. NODE 330 IN THE ABOVE LISTING?

PLEASE CLARIFY
TIA

My suspicion is that node 330 is a tee, and you're looking at only two of the three elements that frame into this node. Find the third element and your questions will be answered.

The stresses can be different at the same node because each element must be in equilibrium. Start with the Force/Moment report, and look at 320-330 and 330-340. You're looking at a free-body diagram. From these forces and moments the "code" equation is applied to compute stresses.