Determination of buckling loads of conical shells using extrapolation techniques

• The applicability of extrapolation techniques in predicting the critical buckling load of conical shell structures is demonstrated.
• Southwell, Massey, and Modified Plots are successfully applied on strain and displacement data and reliable predictions are obtained for the critical buckling loads.
• The proportionality between strain and displacement deformation variables is demonstrated.
• The critical buckling loads of conical shells are satisfactorily predicted through application of Meck Plot method on strain and displacement data.

Shells are thin-walled structures whose stability and performance is governed by geometrical buckling. The buckling stability of shell structures has been investigated through numerous analytical and experimental studies. In an experimental investigation, it is quite important to determine the accurate buckling load of the structure as the critical load is usually masked by failure owing to large deformations as well as the effects of initial imperfections. On this basis, the main objective of this study is to evaluate the applicability of the Southwell, Massey, Modified, and Meck plotting methods in predicting the accurate critical buckling loads of conical shell structures with various geometrical properties. To this end, the buckling loads of several test specimens are determined through application of the aforementioned plotting methods as well as consideration of the test data for strain and displacement deformation variables, and compared with numerical and analytical predictions. Based on the findings of this study, agreement between the extrapolated and numerical as well as analytical results for buckling loads of the considered conical shell specimens is quite satisfactory, which is in turn indicative of applicability of the extrapolation techniques in experimental determination of buckling loads of shell structures.