8-6 Quadratic analysis response surface approximation to the most critical margins using Latin Hypercube sampling of 72 points .............. ...............96.... 8-7 Probabilities of failure calculated by Monte Carlo simulation with 1x106 Samples 97 8-8 Range of design response surface approximations (inch) .............. ...................97 8-9 Cubic design response surface approximation to the probability of failure and probabilistic sumfciency factor (calculated by Monte Carlo sampling of lx106 sam pl es) ................ ...............97.......... ...... 8-10 Optimum panel design............... ...............98. 8-11 Probabilities of failure calculated by Monte Carlo simulation of 1x106 Samples....98 8-12 Uncertainties in material elastic properties (AS4) modeled as normal distribution with coeffcient of variation of 0.03 ................ ...............100.............. 8-13 Uncertainties in material strength properties (AS4) modeled as normal distribution with coeffcient of variation of 0.05 ................ ...............100.............. 8-14 Variation of the random design variables around nominal design value ...............100 8-15 Safety factors used in deterministic design .............. ...............101.... 8-16 Deterministic Optimum (inch, degree, lb)............... ...............101.. 8-17 Quadratic analysis response surface approximation to the worst margins using Latin Hypercube sampling of 342 points............... ...............102 8-18 Probabilities of failure calculated by Monte Carlo simulation of 106 samples (material and manufacturing uncertainties) ................. ............... ......... ...102 8-19 Design history of RBDO based on sequential deterministic optimization using probabilistic sumfciency factor to correct safety factor directly by Equation (8-3)105 8-20 Design history of RBDO based on sequential deterministic optimization using probabilistic sumfciency factor to correct safety factor by actual safety margin using Equation (8-4) .............. ...............105.... 8-21 Design history of RBDO based on DIRECT deterministic optimization with probabilistic sumfciency factor correct safety factor by actual safety margin using Equation (8-4) .............. ...............108....