工程对象的定制与集成

在工程CAD的应用过程中，经常会遇到一些特殊的工程对象，一方面，不同的用户对这类对象会采用不同的处理方法完成设计，出图等任务；另一方面，这些处理方法虽无一致标准，却又有一定模式可循，该文提出了工程模式的概念，讨论了用模板对工程模式进行描述的若干关键问题，并提出了一套模板的设计与实现方法，模板的目标就是组织系统中相关的基本对象以及图形库，公式库，规则库，标准件库等资源，为工程对象提供定制机制，满足多变的应用需求，同时保障定制信息同系统的无缝集成，文章最后以钢结构设计中的难点问题－节点设计为例，论述了基于模板的设计过程。

Customization and Integration of Engineering Object

During the course of the application of AEC CAD, it is usual to encounter some special engineering objects. On the one hand, different users might adapt various methods to design, draw those objects. On the other hand, though the methods utilized do not share a common standard, they are restricted by certain kind of pattern. The paper puts forward the concept of engineering pattern, and discusses several critical issues when using template to describe it. It also proposes a serial of methods for designing and implementing of templates. The objective of template is to organize relative basic objects and resources, like graphic library, rule base, standard component database, etc.. It provides customization mechanism to meet the need of changing requirements, and at the same time ensures seamlessly integration of customized information with CAD system. At last, the application of template technology to connection design, which is known as one of the most difficult part of steelworks CAD, is presented, so as to illustrate the procedure of template based design.