Convex models and interval analysis method to predict the effect of uncertain-but-bounded parameters on the buckling of composite structures

A new, non-probabilistic, set-theoretical models, that is interval analysis method is developed in this study to predict the variability or uncertainty in buckling loads of composite structures resulting from the unavoidable scatter in structural parameters. By mathematically analyzing and proving, the width of the upper and lower bounds on the critical buckling loads calculated by the interval analysis method is sharper than those that are obtained by convex models method, moreover, the interval analysis method has less computational cost than convex models method. Comparison between convex models and interval analysis method is performanced through numerical examples. For the specific cases considered, the results of numerical examples indicate that uncertainties in structural parameters have significant effect on the critical buckling loads of composite structures.