基于STEP标准的CAD产品数据集成系统的研究与实现-机械设计专业论文.docxVIP

Abstract STEP(Standard for the Exchange of Product Model Data)，established by IS0，is an international standard for the computer-interpretable representation and exchange of product data．STEP referenced many existed data exchange standards，especially PDES，and is still under perfecting and expansion．As a unitive internation standard，STEP is supported by many well·known CAD system． This thesis is based on the science and technology project of GANSU province——THE INTELLIGENT DATABASE SYSTEM OF MECHANICAL CAD．some topic arc studied and investigated according to the content on data exchange and share． ．In the first place。the evolution of Product Data Exchange is briefly introduced．Then the slruclure of STEP,the ultimate goal of STEP and its developing policy are analyzed in detail．Its up tO the．minute status of its progress and the introduction of STEP‘S characteristic of contribution to National Industry Information lnfrastrcture ProtocoI are also included． Secondly,the implementation method of STEP standards is mainly analyzed thoroughly,a rel．atively new solve approach to Nm i I data exchanging by using database is put forward，the method of how to build product information model，data dictionary,entity base information form are high lightly introduced,a crucial prob!em to store and fetch product data in database is solved．at the same time an idiographic example is provided． In the fourth paragraph，after analyzing the requirement to the information integration of CAD system，the feature modeling method and realization method are put forward，a prototype system of the product data integration based On feature is provided，at the same time the realization process and‘technology arc expressed，a part information integration system based on step standard is developed，the feature of the part is recognized automatically by this system，at the same time，the information integration WaS contrasted with traditional system，thereby get some character of the information integrat