Effects of elastic buckling at subcritical loads on the load carrying mechanism of a modern passenger ship

Abstract

This work assesses the effect of local elastic buckling on the load carrying mechanism of a modern passenger ship. A qualitative description of the effects the reduced stiffness of elastically buckled structures has on the passenger ship’s load carrying mechanism is provided. The goal is to identify the scenarios in which the reduced stiffness of the load carrying structures must be accounted for. The identification is done through a global strength analysis of a passenger vessel using nonlinear finite element analysis, which better represents the stiffness deviations caused by load shedding in the elastic range, and to compare the results with those obtained from a classic linear static analysis.

The results show how the resulting nonlinearities can significantly alter the load carrying mechanisms at various structural hierarchy levels, even as load levels far below the ultimate limit state, and that simple linear static finite element solutions are unable to capture these effects.

The study differs from previous ones by investigating nonlinear effects on the hull girder at subcritical loads, instead of trying to find the ultimate strength when these nonlinearities are included. This work could be expanded in the future by reaching subcritical load levels closer to the ultimate limit state in order to capture greater global effects of these phenomena, or by implementing more efficient modelling techniques capable of greatly reducing the computational problem size.