Comparison Of4-cargo-hold And3-cargo-hold Finite Element Direct Calculation Of Comprehensive Replenishment Ship

Comprehensive replenishment ships supply fuel, freshwater, foodand weapons to fleets. They provide a credible guarantee to fleets’fighting strength and endurance. Comprehensive replenishment shipscarry not only liquid but also dry cargo. As a result, they havecomplicated structure and loading patterns and there is no unified designstandard yet. To ensure the safety of the2mid cargo holds of the targetship, which contain both liquid and dry cargo, it is necessary to conductdirect calculation of strength of these cargo holds.If we use the conventional3-cargo-hold calculation methods, twomodels are required in order to check the2mixed loading cargo holds,which spends too much time to do the similar work. And what’s moreimportant is that the load cases of conventional3-cargo-hold can’t fullyreflect the complex influence between oil tanks and dry cargo holds. Inthis thesis, direct calculation of strength based on a4-cargo-hold model isproposed, referring to the CSR for Double Hull Oil Tankers. The calculation method includes selection of cargo hold extent, building FEM,selection of boundary condition and load cases, calculation of loads,adjustment of shear force and bending moment, and yield strength andbuckling strength assessment.3-cargo-hold models are also built to compare with the4-cargo-holdmodel. In this thesis, two main aspects of these two calculation methodsare compared, the adjustment of shear force and bending moment, and theyield strength and buckling strength assessment. The result shows thatshear forces keeps the same while bending moments have a deviation inthe third cargo hold after adjustment, and the shear forces and bendingmoments are all the same in other sections of target cargo holds.Thisphenomenon is analyzed in this thesis. However, the comparison ofstrength assessment results shows that this phenomenon of bendingmoment deviation in the third cargo hold has little effect on the strengthassessment, which verified the rationality of the4-cargo-hold FEMdirect calculation of strength.