Probing the buckling of axially compressed thin stiffened cylindrical shells: Stability landscape and nondestructive prediction

Thin shells are highly sensitive to geometric imperfections, and the presence of imperfections reduces their load carrying capacities significantly. Consequently, thin stiffened cylindrical shells are designed conservatively based on the knockdown factor approach that accommodates the uncertainties associated with the underlying imperfections. Recent studies show that methods based on the stability landscape of thin cylinders obtained by probing axially compressed shells in the radially inward direction can predict the capacity of thin shells without measuring the underline imperfections. So far, however, these methods are applied only to thin cylindrical shells without stiffeners. Many outstanding issues must be resolved before applying these methods on thin stiffened cylindrical shells, e.g., the role of stiffeners, the interaction among stiffeners, probing location and imperfections, and the identification of the probing location that yields an accurate capacity prediction. In this study, a stability landscape-based nondestructive procedure is developed for the capacity prediction of imperfect stiffened cylindrical shells by resolving the outstanding issues. Overall, this study reveals three important aspects of the stability landscape-based nondestructive prediction procedure for stiffened cylinders: 1) probing can be used to predict the capacity of imperfect stiffened cylindrical shells without measuring the imperfections, and 2) the probing location plays a crucial role in the accuracy of the prediction, and 3) stability landscape of stiffened cylindrical shells is significantly different than that of unstiffened cylindrical shells.

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