Progressive Collapse Behaviour of Hull Girder of a Bulk Carrier under Longitudinal Bending

A simple method to simulate the progressive collapse behaviour of a cross section of a hull girder is briefly described. Using this method, the progressive collapse behaviour of a cross section of an existing bulk carrier under longitudinal bending is simulated. It was found that the fully plastic bending moment cannot be sustained at a cross section due to buckling of compressed members in the cross section, and that the maximum bending moment carried at the cross section under the sagging condition is 11.5% lower than that under the hogging condition. The influence of corrosion damage in a hold part was also discussed by performing calculation with reduced thicknesses of plating and longitudinals. The ultimate longitudinal strength is reduced by 8% due to a thickness reduction of 4mm in hold plating and attached longitudinals. Results of simulation of a large scale frigate model are also presented to demonstrate the validity of the proposed method.