The Research And Development Of Design System For Parts Based On User-Defined Feature

In the course of product design, the rate of utilization of the typical parts generally accounts for 70-90% designed entirely, so It is very essential to set up the management of the typical parts storehouse and design system. The paper is based on the research and development of the Auto-Design System for Typical Parts,which is a subsystem of the project of design,analysis and simulation of Typical Cross-Country Vehicle by the cooperation of CAD center and SanJiang Aerospace Industry Group Company (SJAGC) of China. Through analyzing some technologies of parts design, a method based on user-defined feature(UDF) for parts design is presented.This paper has analysed the state of development that parts are designed now synthetically and poined out some questions existing at present,such as the singleness of the parts type and the difficulty of parameter driving in designing variable structure; directing against this herein, the research contents of this text is put forward.Through explaining two technologies, namely the technology of component and the second development of Pro/E, the software architecture of parts-design system based on UDF is proposed and component modules of the system are divided; at the same time, fuction model of the system is also proposed and fuction of every module is defined.In order to solve the difficulty when designing part with variable structure, the conception of UDF is introduced and the creating process of it is divided into two steps : that is definition and instantiation. According to its thought, some features are abstracted from commonly used parts and expressed into UDF.The use of UDF makes it so complex to manage all kinds of datas in the system that a method of managing the datas based on UDF is brought forward, therefore datas can be organized intactly and clearly. Based on this, the method, by which the whole model can be created with UDFs modeled together and drivn each independence, is put forward and carried out..On the basis of the above research achievement,a design system for parts based on UDF is development. The system has integrated every component of part design and implemented the process of designing ,checking and modeling of parts. Trid out by SJAGC, the system is stable and credible and has improved the design efficiency of parts.