Suppose the tank settlement is defined by a displacement in vector D1.
Should D1 be added for the sustained stress check? That is, create a sustained case like SUS(W+P1+D1)?
Although displacement is a secondary type loading, in this instance it remains in the system like a sustained loading and does not cycle with temperature.
Another Aspect -
For example if we have OPE((W+P1=T1=D1) minus SUS(W+P1), isn't the result for the EXP stresses going to be very conservative because the D1 component does not cycle?
Paragraph 319.2.1.c (of B31.3) considers settlement as a single cycle effect that does not influence the fatigue life significantly.
How should the load cases for the EXP stresses be setup?
I'll appreciate your answers and insights.
Somnath