Research On Structure Lightweight Desiign And Safety Assessment Of Oil Tanker

At the moment of the transformation and upgrading of the shipping industry,ship lightweight technology has been become a research focus in the industry.After the ship structure is lightened,although it still meets the requirements of specifications and other related constraints,the degree of safety reduction is not yet clear.At present,there is still no relevant safety assessment criteria for lightweight ships,and there is a lack of comparison between optimization results of different intelligent algorithms.Therefore,from the perspective of safety level,based on the lightweight design of oil tanker structure,the paper compares and analyzes the impact of different optimization methods on ship safety,and establishes a safety evaluation system for lightweight oil tankers.The main work is listed as follows:(1)A composed lightweight method for oil tanker is formulated.This paper combines ISIGHT optimization software and MSC finite element software,using parametric finite element modeling technology,optimized Latin experimental design method,radial basis function neural network theory,adaptive simulated annealing algorithm and other technical methods to optimize the design of the oil tanker section.Then it verifies the effectiveness of the optimization results and analyzes the difference between the different optimization algorithms.(2)With the target of ship’s crashworthiness,the nonlinear finite element governing equation of collision is studied.Taking the lightweight the double-hull board side structure as the research object,a lightweight tanker collision simulation model is established.And selecting the lateral vertical collision which is the most dangerous conditions as the accident condition,the impact safety performance of ship sides under different lightweight schemes were calculated and analyzed.(3)Taking the ultimate strength of ship structure as the safety index,the distribution of ultimate hull strength,still water bending moment and wave induced bending moment in the total longitudinal bending limit state equation of hull girder are discussed with emphasis.Then the longitudinal ultimate strength of the lightweight double-hull board is calculated with ABAQUS/Explicit.The effect of structural lightweight on the reliability and failure probability of hull is further studied by first order second moment method.(4)The structure characteristics and task features of oil tanker are summarized,and the optimization design process of lightweight ship is described in detail.The historical accident data of oil tanker is statistically analyzed.Based on the research on the lightweight technology of ship structure and the safety of lightwight tanker,the safety evaluation indicators for lightweight oil tankers are defined,which uses AHP and fuzzy comprehensive evaluation.A risk assessment method for lightweight oil tanker operations is given.