Study On Fatigue Strength And Optimization Of New Hatch Corner Of ULCS

With the rapid growth of international trade,container ships are becoming larger and larger.In the study of structural safety of container ships,fatigue strength caused by stress concentration at the corner of the hatch has become one of the hot topics in the study of large container ships.In order to explore the influence of various cabin corner forms on the fatigue life of container ships,In this paper,a very large container ship of 12200 TEU was taken as the research object in this paper.Firstly,according to the fatigue strength guide of hull structure of China classification society,the middle section of cargo hold was modeled with MSC.Patran finite element software.Secondly,the strength of the hull structure under 24 load conditions corresponding to different wind waves and speeds was calculated respectively under full load and ballast sailing.Thirdly,the Fatigue module was used to analyze the stress of the hot spots in different forms of corner corners of the cargo hold,and the fatigue strength of hot spots with different corner structures was obtained.Finally,through comparative analysis and study,it was concluded that the structure of cargo hold of large container ship was more suitable for the arrangement of hatch corner.This study can provide a certain reference significance for the subsequent hatch structure optimization of large container ships.Some research work is mainly done in the following aspects:(1)Theoretical research.Through systematic investigation and specific data analysis,the fatigue failure principle,cumulative damage theory and fatigue life evaluation and prediction method of container ship cargo hold structure were explored in this paper.(2)Numerical calculation.Based on the classification code of steel seaward ship of China classification society,the finite element software msc.patran was used to establish the model of cargo compartment of ULCS,and 24 load conditions of typical sailing state of the container ship were selected to calculate the strength stress and deformation of the cargo compartment structure of the container ship hull.(3)Fatigue strength assessment.Three different types of cabin corner were selected to refine the fine mesh.The stress and cumulative fatigue damage of hot spots were calculated,and the fatigue lives of different corner forms were calculated and analyzed.Through the comparative analysis of thefatigue life of different shapes of hatch corner,the appropriate form of hatch corner was obtained.