Buckling behavior of a thin-walled cylinder shell with the cutout imperfections

In this work, the effects of geometric imperfections on the buckling behavior of thin-walled cylindrical shells under compression were investigated by both experimental and numerical methods. The imperfections were produced by one or two circular cutouts on the shell surface. The configuration of specimens was fabricated by the geometric imperfection parameter alpha, which was calculated using the circular cutout radius a, thickness t, and cylinder radius R. In the experimental investigation, a three-dimensional (3D) Digital Image Correlation Method, an optical instrument which utilized the full-field and noncontact measurement, was employed to obtain 3D displacement and strains, then the test data were analyzed and compared with the correlation technique that can determine the surface displacements of cylindrical shells. The further numerical simulations showed that parameter a played an important role in the buckling strengths of thin-walled specimens. In addition, the visualization effects of the geometric imperfections on the thin-walled shell structures were also demonstrated by using this optical method.