Buckling of ring-stiffened cylindrical shell under axial compression: Experiment and numerical simulation.

Tanks and silos are often designed as ring-stiffened cylindrical shells. Nowadays, the load-increasing effect of closely spaced ring stiffeners under axial compression has received limited attention in research and practice. Considering the structural safety, the ring-stiffened shell needs to be estimated on the conservative side in practice. This is not desirable in terms of modern lightweight steel structures. However, material efficiency is achieved by combining thin plates with ring-stiffeners. In this paper, small specimen experimental series are carried out to calibrate numerical models, which are subsequently used in parameter studies, because the large-scale experiments are cost-intensive and therefore difficult to carry out in the laboratory. The small cylindrical shells are manufactured by welding of two half-cylindrical shells and the ring stiffeners are spot-welded to the cylindrical shell. Geometric dimension of shell specimens is measured by 3D scanning technology. The measured geometric imperfection information is directly imported into the numerical model based on a mapping relationship and the buckling tests are recalculated by means of geometrically and materially nonlinear analysis with imperfection. The results indicate that the buckling resistance calculated by the Finite Element analysis is very close to that of the test results. The initial geometric imperfection is discussed with reference to the Eurocodes design standard. Furthermore, influence of the ring-stiffener parameter, including imperfection amplitude, radius over thickness ratio, geometry of ring stiffener etc., on the buckling load and knockdown factor is discussed based on a large number of parameter study. • Experimental and numerical study of ring-stiffened cylindrical shells presented. • Geometric imperfections of stiffened cylinder were measured and mapped into FE model. • Ring-stiffener can effectively increase the buckling load of cylindrical shells. • High ring parameter for the heavy stiffened cylinder have positive influence. [ABSTRACT FROM AUTHOR]