Research Of Ship Compartment Modeling System Based On NX Platform

Ship CAD modeling is an significant step during cycle of ship design and manufacture.In addition,during ship CAD modeling,defects in ship design can be found and modified as soon as possible,so as to improve the efficiency of ship design and ensure the quality of design.Among them,compartment modeling is an important part of ship CAD modeling.The results of compartment modeling are the necessary input conditions for ship finite element analysis(CAE)and ship structure design program(SDP).The quality of compartment modeling determines whether the subsequent ship design process can proceed normally or not.Therefore,it is necessary to develop an accurate and efficient ship compartment modeling system.At present,the mainstream ship design software at home and abroad mainly includes FORAN,TRIBON,NAPA,CATIA and so on.The compartment modeling module of these software has some shortcomings,such as poor calculation accuracy,low modeling efficiency,and the modeling results are not intuitive,which are difficult to meet the design needs of the current ship industry.In this study,a complete compartment rapid modeling system is developed on NX platform by using NX secondary development tools.The system integrates the functions of automatic identification of compartment boundary surface,automatic creation of compartment entity,rapid matching of stiffener structure in compartment,and realizes model management and structure management in compartment model by using compartment tree and UDO structure.This system frees the ship designers from the complicated tasks,improves the efficiency of compartment modeling and saves the design cost.In order to improve the efficiency of the frequent judgment of topological relations such as structure intersection and inclusion in this system,a fast search algorithm for ship intersection structure is proposed in this thesis.By using octree structure,the computation amount of the judgment of topological relations is reduced.Based on this algorithm,an Edge segment matching algorithm for intersection seams is developed,and a complete model is established by defining half-face and half-side data structures.The adjacency and intersection relations of the half-face of the panel finally realize the automatic recognition of the boundary surface of the compartment.The algorithm realizes the automatic creation of the compartment from the panel to the compartment,and the modeling speed has been improved qualitatively compared with the traditional modeling methods.In addition,on the basis of the fast search algorithm of ship intersection structure and the space geometry calculation,this thesis develops a fast matching algorithm of child stiffeners in the compartment,which achieves the fast matching between a large number of child stiffeners and compartment structure in the ship.Finally,taking 180,000 tons bulk carrier as an example,the compartment modeling system developed in this study is used to model the compartment.Based on this,the performance of the compartment modeling system is analyzed,and the advantages of the system over the traditional compartment modeling system in terms of calculation accuracy,modeling efficiency,operation convenience and model visualization are verified.