Analysis Of Mechanical Product Design Coupling And Study On Its Redesign Potential

With the development of society,the global market is getting more and more closely linked,which brings in higher level of demands for the innovation and R&D cycle time of enterprise products.By redesign of existing mechanical products,with its design coupling being analyzed and its redesign potential being evaluated,it can help designers identify appropriate redesign products,solve relevant design problems,as well as shorten R&D cycle time of new products.To this end,this thesis has carried out the following aspects of work:Firstly,the coupling problem in the process of mechanical product design is analyzed by exploiting both graph theory and axiomatic design theory.A coupling analysis method based on graph theory is proposed to facilitate design problem solving when the functional requirements are not independent with each other.For the design matrix with coupled design,the path sequencing method of digraph is used to determine the order of function solution;for the design matrix with decoupled design,the concept of minimum coupling term set is proposed,and the elements of the set are determined by digraph,so as to determine the non-diagonal terms to be eliminated,which provides the goal of problem solving for the realization of decoupling.Secondly,the function coupling degree of mechanical product is analyzed from the structural correlation perspective.The relationships between function and structure are categorized as being both direct and indirect.With a two-way comparison method,the correlation degree between function and the directly related structure is calculated first.By analysis of the characteristics of change propagation between the structures,a change propagation tree from function to the indirectly related structure is subsequently constructed to analyze the correlation degree between the two.Finally,through the synthesis of both direct and indirect correlation values of function and structure,the coupling degree of function is calculated.Thirdly,the functional requirements of the redesigned products are analyzed.According to the functional requirements put forward by customers,based on the relevant knowledge of KANO model,a questionnaire survey is carried out to obtain the satisfaction evaluation table of users for various functional requirements.Through further analysis,the membership evaluation vector of various functional requirements is obtained.On this basis,the clustering analysis is carried out to determine the functional requirements set favored by the customers,so as to help designers design better products.Finally,the redesign potential of mechanical products is studied.Based on the theory of information entropy and the research results of structural relevance,a potentiality evaluation model of mechanical product redesign is proposed.The influence degree(front-end)and complexity of change(back-end)caused by redesign are analyzed synthetically,and the quantitative value of redesign potential is obtained.The effectiveness of the model is finally verified by an example.This provides technical support for the designers in determining appropriate redesign products.