Prediction of the buckling capacity of thin shells by using stability landscapes

The prediction of thin cylindrical shells’ buckling capacity is difficult, expensive, and time-consuming, if not impossible. This is because the prediction requires a priori knowledge about the imperfections that are present in the cylinders. As a result, thin cylindrical shells are nowadays designed conservatively using the knockdown factor approach to accommodate the uncertainties associated with the imperfections. A novel approach is proposed, which provides an accurate prediction of cylindrical shells’ buckling capacity without measuring the imperfections. The proposed approach is based on the stability landscape that is obtained by probing axially compressed cylinders in the radial direction. Computational and experimental implementation of the procedure yields accurate results when the probing is done in the location of the highest imperfection amplitude. However, we observe that the procedure over-predicts the capacity when the probing is done too far away from that point. Further, we investigate the effect of probing location, imperfection amplitude, and background imperfections on the accuracy of the prediction. This study demonstrates the crucial role played by the probing location in nondestructive predictions of the buckling capacity.