Study On Ultimate Strength Calculation And Assessment Of Container Ships

At present,in the design and strength calculation analysis of ships and marine engineering structures,the strength specifications and safety performance requirements of various classification societies are becoming more and more stringent.The strength standard verification methods that have been used in the past can no longer accurately represent the structure's real ultimate capacity and the process of destruction,the ultimate strength has gradually been considered as a key indicator in ship design,especially in initial design,strength calculation and checking.In this paper,based on the nonlinear finite element method,a 10000 TEU container ship ultimate strength has been studied.Based on the research progress of the ultimate strength and the related calculation methods,concerning the ultimate strength of rectangular plates with circular and obround openings under axial compressive loads,plate slenderness ratio and hole size are taken into account in this paper.The ultimate strength of a large number of perforated plates was calculated by NFEM and a series of empirical formulas under four boundary conditions were proposed based on new best-fit regression analyses.The accuracy of the empirical formulas proposed in this paper was verified by comparisons with the corresponding experimental results and more finite element analyses results.This paper studied the influence of the grid size and the cell characteristics on the ultimate strength of a typical box girder.Comparing with the related test results,it is shown that the NFEM has accuracy and rationality for calculating the ultimate capacity of ships.Secondly,the ultimate strength of a 10000 TEU container ship hull under bending and torsional loads is calculated and analyzed,and its failure mode is analyzed.The envelope curve function of the ultimate capacity of the hull under bending-torsion combined load is proposed.CCS,UR-S11 and UR-S11 A rules has been used to check the ultimate strength of the structure.In addition,the influence of lateral loads including cargo pressure and outboard water pressure on the ultimate capacity of large container ships is studied.According to the thin-walled mechanics,the ultimate strength test design method of a container ship was put forward.