where we have to exact location of Stress Classification Line (SCL).
I have gone through ASME sec VIII Dev.-2.( ANNEX 5.A :LINEARIZATION OF STRESS RESULTS FOR STRESS
CLASSIFICATION), But I didn't get the point.


Why 'SCL'is taken at low stress region (as shown in figurein the atachment document), eventhough the stress is high very far from the discontinuity?. I have gone through ANNAX 5.A.3, still I am getting confuse to locate the SCL.

Dear Shri.Pradeep

'SCL' taken at low stress region (as shown in your attachment) is not adequate.

Annex. 5.A.3 does not mention so (that is take SCL only away from discontinuity); In fact Anenx 5.a.3 shows examples near discontinuity ; One takes SCL away from discontinuity to verify result with closed form solution (example hoop stress under pressure loading - one should take sufficient away n (sqrt(RT), where is bare minimum 1 and can be 2 or 3 depending on accuracy looked for - beam on elastic foundation concept.

Hence the analyst has to take SCL at all critical location near discontinuity. With experience and looking at geometry and stress contour, an expert will be able to make out which SCL gives maximum membrane or bending stress.

In otherwords consider thal SCL which gives maximum membrane and bending stress to arrive at PL or Q as the case may be.

I hope I have made it clear
With regards
R.SRINIVASAN

_________________
R.SRINIVASAN
Sr. VICE PRESIDENT
Head, Design and Engineering
PED,ISGEC,
YAMUNANAGAR
HARYANA -135001
INDIA

Thank you very much Mr.srinivasan for reply.

(1)Waste Heat Boiler pass-2(WHB-pass-2) was designed based on Sec VIII-dev-1. I did FEA (Elastic alysis only) for this WHB-pass-2,because the knuckle is not covered under design by rules(VIII- dev.-1). I have comparing stress intensity at SCL aganest Max allowable stress intensity based on VIII- dev-2. When I am plotting stress intensity plot at nearer to discontinuity to far from the discontinuity, it is varing form parabolic to linear. in some literature I found that at SCL the shear stress plot ( stress intensity plot) should be minimum parabolic. Is it true?

(2)Is it SCL location is same for elastic analysis and plastic analysis?

(3)In some cases SCL will take at discontinuity and in some cases away form discontinuity. Why is this?. I am getting high stress intensity at some discontity locations why shouldn't consider these values. I think wherever it is the equipment shouldn't experience the high stresses. for ur reference see figure:1 (stress intensity plot) and WHB-SCL_Lines.pdf (SCL lines)