| Deformation of parts during assembly cannot be ignored.During the current assembly operation,aiming at the problems of repeated trial,waste of parts after trial fitting deformation,and difficult to control the assembly accuracy,etc.Technology of the assembly accuracy prediction and repair simulation based on finite element analysis are proposed.Constructed a hybrid model of the ideal design model and the finite element model and realized the associated fusion of the two related data.Calculation and analysis prediction of typical assembly accuracy of parts are based on mating feature nodes,and then based on multi-objective function solution to get the optimal assembly positioning posture.Design and optimization of repair schemes for products based on response surface method and fuzzy evaluation method.An assembly precision prediction and repair simulation system for products is developed to provide technical support for the assembly and repair of products considering deformation.The first chapter discusses the research background of this article.This chapter introduces the domestic and foreign research status of the expression method of Virtual assembly model based on mixed data of multiple kinds of models,the assembly positioning and the prediction of assembly accuracy of virtual assembly which considering deformation,and the evaluation of repair simulation and repair ring selection.The research progress and existing problems of the above technologies are analyzed,and the research content and significance of this paper are put forward.Finally,the organization structure of this paper is introduced.The second chapter builds a hybrid model of product virtual assembly fused with finite element data.According to the requirements of assembly accuracy analysis and repair simulation in virtual assembly of parts,establish a virtual assembly hybrid model of ideal geometric model and finite element model,which associative fusion in terms of geometric features,position constraints and physical properties.The hybrid model lays the data foundation for subsequent assembly accuracy prediction and data transfer of repair simulation.The third chapter proposes the method of the assembly accuracy prediction and optimization for parts considering assembly deformation.Based on the positioning and assembly process of parts,the assembly accuracy prediction of parts considering assembly deformation is performed.Calculate the key indicators in the actual assembly of parts such as profile accuracy,assembly gap and assembly step based on the data of the mating feature nodes.Finally,the assembly accuracy prediction and deformation data are combined to optimize the pose and position of the part.The fourth chapter puts forward the design and simulation method of parts repair scheme based on finite element simulation.Aiming at the problem that the assembly deformation of parts cannot be ignored during the assembly process,a repair plan design of parts based on response surface method is proposed to ensure the assembly accuracy of parts after assembly deformation.Based on the fuzzy comprehensive evaluation method,the selection and evaluation of the repair ring is performed.The fifth chapter develops a simulation system for product assembly accuracy prediction and repair.Based on the hybrid model construction,assembly accuracy prediction and repair simulation method,combined with software such as Unity3 D,SQL Server,Ansys Workbench,etc.,the development of a virtual assembly and repair simulation system for products has been completed,which include hybrid model data management module,virtual assembly accuracy prediction module and repair simulation module and applied to the assembly of thermal protection systems and turbine blades.The sixth chapter summarizes the full paper,analyzes the shortcomings of this paper,and looks forward to future research work. |
