Study On The Strength Of Large PCTC With Different Flexible Structure Design

Car carrier is a kind of high tech and high value added ship.In addition to carrying a variety of commodity vehicles,it can also carry containers and other grouped goods.The ship structure of the car carrier differs from other conventional ship types in that it does not have a transverse bulkhead in the cargo area,and the transverse strong frame is mainly used to bear the lateral strength of the hull.In addition,the number of decks of the car carrier ship is relatively high,so the ship's center of gravity is high and its stability is poor,especially when the ship is subjected to an asymmetric load caused by waves,wind and other factors,the problem of the lateral strength of the car carrier is even more prominent.In order to alleviate the lateral strength of the car carrier,the Norwegian Classification Society first proposed the concept of flexible design,however,domestic research on this aspect has yet to be improved.The research takes the 7800 PCTC as an example,and the structural strength of car carrierunderdifferentflexiblestructuredesignisstudied.Inthispaper,themaincontentsareasfollows:1.Using theMSCPATRANsoftware,finiteelement modelsofthecabin underdesign schemesof flexibledeckinitiallayerisdifferentwereestablished.2.Refer to the Norwegian Classification Society and the Italian Classification Society to determine the calculation conditions and calculated loads of the ship in the Forward and Racking condition and with the aid offinite element solverMSC NATRAN does direct calculation of the cabins underthesevendesignschemes.3.Comparing and analyzing the structural strength results of the seven design schemes,looking for the law of the influence on the structural strength of the hull under different initial layers of flexible deck.Thenareasonableflexibledeckinitiallayerdesignisobtained.4.Under the flexible structure design,the effect of the change of the flexibility grade of the longitudinal elastic strips used to connect the deck strong beam and the side stiff ribs on the structural strengthofthehullisstudied.The research results of this paper can provide reference for the design of Car Ro-Ro ship in the future,and have certain engineering application value.