Collapse Behaviour of Ship Hull Girder of Bulk Carrier under Alternative Heavy Loading Condition

摘要

For a bulk carrier in alternative heavy loading condition, it is noted thatrnthe double bottom of an empty hold is subjected to both longitudinalrnthrust due to hull girder bending in hogging and local bending causedrnby high pressure loads on bottom plating. In order to examine therninfluence of local bending of double bottom on the ultimate hull girderrnstrength, a series of nonlinear calculation is performed applying threerndifferent methods. The first method is Smith’s method using in-houserncode, HULLST, to evaluate ultimate hull girder strength under purernbending. The second is the application of new system recentlyrndeveloped by the authors. This method is a combination of load/motionrnanalysis and progressive collapse analysis. The third is nonlinear FEMrnanalysis using a commercial code, MSC.Marc. It has been found thatrnbending deformation is produced not only in double bottom but also inrnbilge hopper tank, and the ultimate hull girder strength is reduced byrnroughly 20% due to this local bending.