my current calculation consists of a Tank which operates on +100C and -20C. it settles down by 150mm during operation. my load cases are as follows:

1- W+T1+P1
2- W+T2+P1
3- W+T1+D1+P1 (D1: settlement+tank bulge+radial expansion)
4- W+T2+D1+P1
5- W+P1 (sus)
6- L3-L5 (exp)
7- L4-L5 (exp)
8- L6+L7 (exp) (COMBINATION METHOD: abs)

if I add case 8, the displacement of the nozzle will be 300mm downward which increases the risk of going bust. I would like to know if it is really necessary to combine two expansion cases with an induced displacement in a scalar method.

Regards

My opinion:

1- W+T1+D1+P1(D1: tank bulge+radial expansion)
2- W+T2+D2+P1(D2: tank bulge+radial expansion)
3- W+T1+D1+D9+P1 (D1: tank bulge+radial expansion; D9: settlement)
4- W+T2+D2+D9+P1 (D2: tank bulge+radial expansion; D9: settlement)
5- W+P1 (sus)
6- L1-L5 (exp)
7- L2-L5 (exp)
8- L3-L5 (exp)
9- L4-L5 (exp)
10-L1-L4 (exp)
11-L2-L3 (exp)

Dan,

I believe the load cases 1 to 4 that I have considered are more conservative since, if the nozzle loads on all those four cases pass, it will be covering all potential cases in between. about your other load cases, I do not see any difference between cases L10 and L11. could you clarify? (I reckon the combination methods remain algebraic)

thanks

PS I wrote this before I saw your edited comment. now it makes sense.