Effects of ringed stiffener on the buckling behavior of cylindrical shells with cutout under axial compression: Experimental and numerical investigation

In practical engineering, cutouts in thin-walled cylindrical shells are usually welded with ringed stiffeners for the purpose of connect and seal. In this paper, experimental and numerical studies have been conducted to investigate the effects of ringed stiffener on the buckling behavior of perforated cylindrical shells under axial compression. Three test specimens with ringed stiffener and three specimens without ringed stiffener are manufactured and tested. The mid-surface imperfections of all specimens are measured and introduced into the finite element model. The finite element method using static analysis with artificial damping is used to simulate the displacement controlled compression tests. Good agreement is found between the numerical and experimental results. It is found that the global buckling loads of perforated shells are improved by ringed stiffener. The larger the cutout size is, the more obvious improvement shows. In addition, effects of ringed stiffener on axial stiffness and imperfection sensitivity of perforated shells are studied in details. The relationship between ringed stiffener thickness and global buckling load of perforated shell is also discussed. Meanwhile, a critical thickness parameter k of approximately 15% is proposed.