Research On Establishment And Application Of Final Forging Billet For Turbine Blade

Turbine blades are the most abundant and diverse parts in turbine machinery.The forming quality of blade billet is directly related to the energy conversion efficiency of turbine machinery.Due to its unique advantages of simple operation,high mechanization degree and high productivity,die forging is widely used in enterprises at home and abroad to complete the final forging process of turbine blade,and its accuracy is guaranteed by mechanical processing.However,the initial billet design needs a lot of energy,and its efficiency can not meet the needs of enterprises,which increases the production cost of blade manufacturing and restricts the development of the whole blade manufacturing industry.Therefore,this thesis established the turbine blade forging billet database,through the research of turbine blade billet finish forging forming process,using knowledge engineering techniques for analysis and design at the same time.Then developed an auxiliary system for rapid billet design to realize the standardization,automation and systematization of the application process of final forging of turbine blade billet database.The main contents are:(1)By studying the final forging process of turbine blade billet,took RA1142 blade as an example,DEFORM-3D software was used to carry out numerical simulation.Based on the response surface optimization method,a comprehensive optimization function was proposed,which took billet structural parameters as independent variables and the flash allowance,die load and forging deformation uniformity as objectives.The quadratic polynomial regression model was used to obtain the optimized billet structure,and the result of simulation verification showed that the billet mold filling was full and all the objectives were improved significantly after the final forging.Finally,the optimization rules of the design variables of the optimal comprehensive index were summarized.(2)Combined with the production experience and the structural characteristics of turbine blade billet design,the calculation forms and application rules of the dimension parameters of the main design parts were summarized,and the knowledge was expressed and processed in a standard manner.According to the analysis of specific functional requirements,the overall functional framework of the turbine blade billet database was constructed,and the conceptual model and physical model of the billet database were designed.The billet database was divided into four main modules,and established by relational database software My SQL Server5.5,which stored the product information of the blade,the corresponding billet information and the parameter information of the typical billet structure.The data extraction of the blade billet and the management and maintenance of billet database were realized by SQL language,and the correlation with three-dimensional model library was established.(3)In order to solve the problems of low efficiency in the retrieval and reuse of billet instances,a hybrid reasoning mechanism based on rules and examples was used to deduce the information of blades based on the characteristics of high serialization of finished forgings and corresponding billets.The input information was divided into three main modules by analytic hierarchy process,based on case reasoning and the nearest neighbor strategy,The similarity algorithm which can represent the characteristics and value types of each attribute was proposed to significantly improve the efficiency of problem solving and facilitate the matching and reuse of knowledge.(4)Based on UG secondary development technology,through Visual Studio platform programming,the concrete application of turbine blade final forging billet database was realized.In order to improve the efficiency of billet design,based on customer’s technical requirements parameters and blade related information,developed an interactive billet reuse system to realize the blade billet instance retrieval with the highest similarity.At the same time,the type of the blade and corresponding billet were displayed in the results,then export the model and get the expression.The model was modified to a certain extent according to the optimization rules of each design variable and updated.Finally,the feasibility of the technology was verified by a specific design example.The research content of this paper made full use of the existing design knowledge,to a large extent,reduced repetitive labor,and meet the actual production requirements of turbine blade billet design,which had the characteristics of flexibility,speed and reliability,at the same time,increased the market competitiveness of enterprises.