Research On Load Inversion Method And Model Experiment Of Ultra Large Ships

In recent decades,with the vigorous development of shipbuilding industry,the principal dimensions of ultra large ships are also increasing.That is in order to further improve the shipping capacity,reduce the transportation cost and increase the profit margin.However,it also brings serious hidden dangers to the navigation safety of ultra large ships due to the huge bow floating and large deck opening.These cause bow slamming and bending-torsion coupling effect.By installing and laying the sensing system on ultra large ships,through the response data of the structure under wave load,the external load by ultra large ship is inversed in the navigation process,so as to provide early warning and auxiliary decision-making suggestions for the structural safety.Therefore,it is of great practical significance to enhance the structural safety of ultra large ship structure by avoiding overload.In view of the above background,this paper studies the load inversion methods of ultra large ships in the following aspects:1.Based on the bending-torsion coupling problem of ultra large ships,a load inversion algorithm of bending-torsion decomposition of ship cross section is proposed.Based on the average longitudinal strain of two adjacent cross-sections,the bending moment and torque coupled together in the practical navigation of ultra large ships are decomposed.And then the design of the keel girders takes the parallel middle of an ultra large container ship as the parent structure.Through the finite element simulation and model experiment,the reliability of the algorithm is verified;2.Based on the problem of bow slamming of ultra large ships,a load inversion algorithm of bow slamming is proposed.Based on the structural response of the bow slamming region,the slamming load amplitude in the slamming region is inversely calculated.And then the design of the stiffened plate takes the slamming region of an ultra large container ship as the parent structure.Through the finite element simulation and model experiment,the reliability of the algorithm is verified;3.Taking the cargo hold structure and bow structure of an ultra large container ship as an example,the design loads are applied respectively.Through the bending-torsion decomposition algorithm and the bow slamming load inversion algorithm,the reliability of the two algorithms in the real ship is further verified.