Hi, sorry for bother! I build a kriging model, and based on the kriging I use Performance measure approach, Single loop approach, Sequential optimization and reliability assessment for RBDO.
Plot for RBDO - Convergence of the Constraints are obtained.
But what’s the meaning of G for vertical axis in the plot?
Best!
In the three pictures, G all converge to 0. But why?
Dear @AmosJoseph
In these plots, G is the value of the limit-state evaluated at the minimum performance target point (MPTP). Please have a look at Section 1.3.1.3 of the RBDO manual for more details on what this point means. It is basically used to transform the reliability problem into a deterministic one.
When the constraints are saturated, that is P_f(d) = Pf_target, then the G(MPTTP(d)) = 0. The plots therefore say that, at convergence, all constraints are satisfied and saturated.
Best,
Moustapha
Hi, pardon.
G for Performance measure approach and Sequential optimization and reliability assessment are all 2.3934e-06.
G for Single loop approach is -3.2085e-08 < 0.
The value of the limit-state evaluated at the minimum performance target point (MPTP) must be larger than 0 so that system is safe.
So the system is in failure state and results obtained by Single loop approach can’t be used?
Best
