Reliability-based design optimization of stiffened panels

We explore reliability-based designs of isogrid stiffened panels. Uncertainties in material properties and geometric manufacturing uncertainties are represented by random variables. Due to the multiple failure modes in the stiffened panels, polynomial response surface approximation are fit to the most critical safety margins in the panel. Probability of failure is calculated by Monte Carlo simulation using the polynomial response surfaces. A probabilistic sufficiency factor approach is employed to facilitate the design optimization.