Finite Element Analysis of Longitudinally Stiffened Cylinders in Bending

Abstract

This paper presents the construction, verification, and utilization of a finite element model for longitudinally stiffened large diameter fabricated steel cylinders subjected to bending. The model is based on a large deformation elastoplastic incremental formulation. Three-dimensional degenerated plate-shell elements were used for both shells and stiffeners. The model incorporates both initial imperfections and residual stresses. It was used to predict the results obtained from five large-scale fabricated steel cylinders tested in the laboratory. The buckling modes, ultimate moments, and the moment versus curvature behavior of the numerical models were all in good agreement with those obtained from the test results. To expand the database, a total of 13 cylinders with a wide range of parameters was analyzed using the same finite element model. The parameters included the geometry of the cylinders and the stiffener arrangement. Measured initial imperfections and welding residual stresses obtained from the physical tests were applied to the numerical models using mapping procedures. The effects of residual stresses and initial imperfections were examined through the analysis of six additional cylinders.