Digital image correlation-aided non-destructive buckling load prediction of cylindrical shells

The buckling capacity of a thin cylindrical shell depends on the unknown existed imperfections. Therefore, the prediction of the shell buckling load is still challenging if not impossible. In this paper, the prediction of critical buckling load of axially compressed cylindrical shell is investigated based on the novel non-destructive probing method. In order to find the proper locations for probing, we have combined the digital image correlation (DIC) technique with the non-destructive probing procedures. We have designed and built a 360° three-dimensional (3D) DIC system to reveal the displacement fields of the cylindrical shells and especially the commercial aluminum cans under axial compressions. Through the combination of experiments, numerical simulations and theoretical analysis, nonlinear force-indentation responses of the imperfect shells with non-zero local Gaussian curvatures to the point indentation were analyzed to guide the choice of the proper locations for the indentation. Our results demonstrate that the buckling load prediction of imperfect cylinders is possible if the probing is done sufficiently close to the dominating imperfection location, which could be detected and localized using the DIC technique.