Topology Optimization Design For Openings Of Hull Components Based On Lightweight

The topology optimization of the hull structure can reduce the weight of the structure and improve the mechanical performance of the structure under the condition of meeting the strength of the hull structure,thereby achieving the purpose of lightening.In the field of modern ship structure optimization,most of the researches mainly focus on the hull structure layout and size optimization,and there is little involved in hull structure topology optimization.The most typical topology optimization problem of hull structure openings are particularly important for the lightweight design of ships.During the design and construction of the hull structure,manholes,lightening holes,process holes,etc,need to be opened.The existence of openings will increase the stress at the edge of the hole and even cause stress concentration.In addition,with the increase in structural lightweight requirements and the development trend of large-scale ships,traditional opening design can no longer fully meet the requirements of today’s hull structure design.It is necessary to take various design conditions and structural strength and functional requirements into account,in order to reduce the weight of the hull structure and improve the mechanical properties and material utilization of the hull plates.Therefore,carrying out multi-condition hull structure and opening topology optimization have important theoretical value and practical engineering significance for reducing the weight of hull structure,improving the level of hull construction,saving economic resources,and improving the level of lightweight design of hull structure.This paper takes the hull opening structure as the research object,and improves the traditional BESO optimization algorithm.Combining the compromise planning method and the satisfaction theory,the I-BESO algorithm for multi-condition hull opening hole pattern optimization and the I-BESO algorithm for multi-condition hull structure topological opening are obtained.On this basis,taking the local area structure of the cruise ship as the research object,carrying out iterative optimization of hole position and hole pattern,discussing the optimization of single-type openings under multiple working conditions and the coupling optimization of multiple types of openings,forming a better opening Position,formulation and size parameters.The main research contents are as follows:(1)Summarizing and sorting out the principles of hull openings,studying the research progress of topology optimization methods at home and abroad,and analyzimg the research application status of ship structure optimization and topology optimization methods in the ship field,and clarifying the research significance and main research content of the thesis.(2)Introducing the implementation principle,optimization criteria,performance index formulas and optimization process of the traditional BESO algorithm;improving the traditional BESO algorithm,introducing optimization objectives and stress constraints,and participating in the optimization iterations of the hole edge elements,and improving element deletion and addition Through the single-hole optimization and the double-hole collaborative optimization,the feasibility of the improved method is proved,and it lays the foundation for the subsequent development of multi-condition hull structure plate opening topology optimization.(3)The compromise planning method and satisfaction theory are introduced into the I-BESO algorithm,and the volume reduction ratio is the optimization objective,and the hole edge stress is the constraint.The optimization algorithm is suitable for the opening position and the hole pattern iteration of the hull opening structure under multiple conditions.The second development is embedded in the large-scale finite element program ANSYS,and the single-hole optimization and the double-hole collaborative optimization of the perforated thin plate are carried out,and the opening position and pass type of the hull girder web are optimized,verified the feasibility of the two optimization algorithms.(4)Taking the cruise ship beam web openings,side openings,and T-material penetration holes as the research objects,the three types of opening structures are optimized.In addition,the hole position and hole shape are optimized for the non-opening structure of the side girder,discusses the maximum stress,average stress and the change of the hole type and volume of the four types of openings after topology optimization,and reconstruct the optimized openings to analyze the mechanical properties of the new openings.(5)Taking the finite element model of the cruise cabin structure as the research object,three types of openings are selected: side openings,deck stringer openings,and through holes,and the coupling topology optimization of different types of openings under multiple working conditions is carried out,and the analysis is different.Types of openings are jointly optimized for topology,and the optimized three types of openings are reconstructed.The reconstructed openings reduce the structural weight while meeting the structural strength requirements,and achieve the purpose of lightening.