Construction And Implementation Of Welding CAPP In Mechanical Engineering Field Based On Object-Oriented

With the application of computer technology in manufacturing industry more and more widely,traditional CAPP system was unable to meet the specialized welding process development because ofa growing heavy welding process preparation. Especially in the field of Mechanical Engineering,welding procedure qualification standards which were characterized by complexity and quickupdating were strictly used in welding process preparation. In the paper, the Object-Oriented method,Expert System method and CAPP technology were used for the demand of the weld process of theMechanical Engineering field to design expert welding CAPP system based on object-oriented. In thesystem, some systems were used together to help engineer to prepare welding process, such as thebasic database and weldability analysis system, the welding process design system, welding procedurequalification system and welding material quota system.In welding basic database and weldability analysis system, steel basic data and weldabilityknowledge were stored in related entity class and relational database which were constructed byobject-oriented method, for example, the chemical composition and mechanical properties of steel, thetrademark comparison of home and abroad steel and so on. Another, weldability calculating wasdesigned, the models of which were summarized in the paper, which contained the minimum preheattemperature, the t8/5and so on. Thus, the welding basic data and knowledge were well shared to laythe foundation of the welding process designing.In welding process designing system, the Expert System method was used to construct weldingprocess database, welding process knowledge and comprehensive reasoning mechanism reasonablyfor the computer aided automatic designing of welding process. Another, the steel weldability wassearched by element weights method for helping welding process designing to improve the accuracyof the process designing.In welding procedure qualification system, the Qualification Necessity Judgment and theQualification Feedback Judgment were implemented according to field standard NB/T47014-2011,the WPS file and PQR file not only could be edited but also could be managed effectively, whichcould not only provide great convenient for daily work of the enterprises but also avoid the repeatedqualification and missing qualification. Thus, a lot of cost could be saved.In welding material quota system, the welding material quota calculation was implementedaccording to the summary of the welding material quota calculation model of common weld method and calculation model of the cross-sectional area of the groove that was based on the grooveparameterized method and iteration method. And the welding material quota data was managedeffectively. Another, the correcting coefficient was put forward to improve the accuracy of the quotaresults.In the paper, the development and designing of the welding expert CAPP system of MechanicalEngineering field was implemented according to Object-Oriented method, and an easy to extend andmodify computer aided process planning system was formed, which would be applied in MechanicalEngineering field.