Analysis Of Structural System Reliability Of An Inland Waterway Bulk Carrier

In recent years,due to the increasing complexity of ships and marine systems,the ever-expanding scope of work,and the higher requirements for the overall architecture and life-cycle capabilities of ship systems,traditional calculation methods do not solve the problems perfectly.The use of reliability theory to analyze ship structures,especially large ship structures,is of great significance.The purpose of reliability analysis of structural systems is to find the main failure modes of the structure and to determine the failure probability of the structural system,to get an intensity analysis result that is more in line with the actual ship structure.This paper analyzes the reliability of the structural system for an inland waterway bulk carrier.The details are as follows:(1)With the help of the secondary development of Auto CAD software and the secondary development of ANSYS software,it is possible to quickly build the finite element models from the CAD drawings of ships.(2)According to the actual situation of the ship,the finite element model of the spatial beam-slab structure of the structure is established,and the plate elements in the ship are simulated by the equal-shear-stress rectangular element and the equal-shear stress triangular element,and the uniform rib unit is used to simulate the reinforcement ribs in the ship.The beam elements in the ship are simulated by space hybrid beam elements;the external loads are equivalently applied to the nodes,and the calculation results of the self-edited FORTRAN procedure and ANSYS software are compared and analyzed,to prove the correctness of the theory and procedure.(3)Based on the ship plate unit thickness,beam element cross-sectional area,external load value and material strength value,the limit state function equations of plate element and beam element are established respectively,and the improved second-order moment method is used to obtain the component.The validity and correctness of the results was verified by the Monte-Carlo method.(4)Based on the branch and bound method,the main failure modes are searched,and the failure probability of the main failure modes is obtained by the complex correlation equivalent plane method.The failure probability of the structural system is selected and calculated based on the PNET method and the reliability of the results is verified.The structure is proposed.System failure is caused by the continuous failure of several local components,the weak parts of the structure are determined,which provides effective technical support for ship structural reliability design.