Hi Mr/Ms,
I am making a tank nozzle check by means of API 650-P,when i choose "Stiffness Coefficient",i need to check Figure P.2a.The parameter I calculate a/R=0.008 and R/t=1180,the curve a/R=0.008 is between curve a/R=0.02 and a/R=0.005,but I am hard to find where is the accurate loacation for curve a/R=0.008,it is too indistinct to choose this curve,thus I will choose a curve that take a big error for my calculation.
My question is:
1,Do anyone have a good methoed to solve above problem.
2,How did authors choose "Stiffness Coefficient" when he wrote API 650-P ,just by means of checking Figure,i don't think so.
3,Whether anyone have a equation instead of these curve when he choose these parameter"KR/E(2a),KL/E(2a)3,Kc/E(2a)3,YL,YF,YC",if anyone has the article or documents ralated,please share with me,my mail-box is sxhwzq@hotmail.com.
I look forward to anyone can response me soon.
Tks a lot,
Best wishes and warm regard,

a good learning student