Direct Strength Analysis Of Ship's Structure Taking Account Of Thermo Stress

Holistic-cargo tank type asphalt carriers have the advantages of higher efficiency of capacity utilization, facility of cleaning up, and so on. So they are popular with ship-owner. But it is necessary to analysis the thermo stress of the hull because the high temperature affect all the hull structure which result in the decline of the mechanistic character of the structural material.This thesis takes a 3500t asphalt carrier as an example. The structure of the asphalt carrier is analysed and assessed by FEM software MSC.Patran&MSC.Nastran. The processes are as follows:①The structure modeled by the Patran software. All the cargo tanks are a diathermanous integer. So the model which based on the relational regulation of Guidelines for Direct Strength Analysis of Oil Tanker (2003) involved all the cargo tanks.②Define the property of heat transferred-model, apply on relevant boundary conditions, and analyse the process of transferring heat. Gain the distributing temperature of fully loaded and half loaded, and set up relevant temperature field.③Confirm boundary conditions, temperature load (transform the calculated temperature to the temperature load), liquid cargo pressure, and external sea pressure.④Apply the boundary conditions and calculating loads on the model.⑤Analyse the thermo stress of six calculating conditions of the model, pick up available results and assess them.⑥Analyse the heat transfer process and the thermo stress of "1/2+1+1/2" model.⑦Summarize and assess available results of two models.⑧Put forward advantaged points.According to the calculation and study, utilizing FEM to analyse the asphalt carriers'three-dimensional steady temperature field and structural stress taking account of thermo stress is feasible.Two calculating model can use for direct strength analysis of the carrier, and the result of the "1/2+1+1/2" model can satisfy required precision in engineering, which reduce largely the FEM workload in calculating.