Increase of Warping Rigidity in Open Sections of a Containership by Stiffening Plates

Distributions of warping stress and deformation of modules with open-section and longitudinal stiffening plates were determined by a finite-element program. Eleven models of various stiffnesses and configuration but under the same torsional moment were studied. The loading and overall hull size are close to a containership of 38 000-ton loading capacity. The prismatic thin-walled beam analysis was performed on a model to compare the results from the finite-element approach. It has been found that the warping rigidity can be effectively increased by installing plates along the axis of the ship. The maximum warping stresses, which are usually found at the hatch corners of the wing boxes, are evaluated and compared.