Assembly Evaluation For Complex Structure Products

Assembly accounts for 20%-70% of manufacturing costs and 40%-60% of manu- facturing time in the modern manufacturing industry. Based on the situation of fierce competition among enterprises in the global market,"Design For Assembly"was presented in order to develop new products and respond market rapidly.Assemblability evaluation as an important part of DFA did fully take into account of assembly in the upper reaches of the design stage,avoided the design mistakes in the upper reaches which lead to long product development cycles and high development costs.On the basis of analyzing factors that affect the assemblability of products , a fuzzy evaluation model for evaluating the assemblability of products was presented by using the method of"Fuzzy Comprehensive Evaluation + Analytic Hierarchy Process".The assemblability evaluation system both at the level of parts and products were implemented, which provide designers a friendly and easy-use designing environment and tools. Therefore, the on line designing system can be realized and the process of product design can be guided toward "good for assembly" from the beginning of product design.Based on above researches,we established a CAD-DFA integrated system environment,in which designers can analyze and evaluate the performance of assembly,detect interferences among parts and simulate assembly process. The result of assemblability evaluation can be returned to CAD system in order to redesign the product.