附加自由曲面构造框架及其有效性维护的研究*

在对HUST-CAID(哈尔滨理工大学计算机辅助工业造型设计)系统进行研究的基础上，首先引入了自由曲面特征，然后结合HUST-CAID系统定义了自由曲面特征的分类和参数化，应用这种分类和参数化的方法创建了一个自由曲面特征，提出了一种基于FFDP配置的附加自由曲面特征的构造框架。此框架可以使自由曲面整体模型的构造完全参数化。最后建立了基于这个框架构造的自由曲面附加特征的有效性维护机制，从而达到对自由曲面附加特征进行有效性维护的目的。

Study on construction of freeform feature models with attachment and validity maintenance

This paper introduced the freeform feature modeling in HUST-CAID, defined classification and parameters combining with the HUST-CAID system (computer aided industry design system developed by Harbin University of Science and Technology), creating a freeform feature by this classification and parameterization. On the basis of configuration of FFDP,put forward a framework for attaching freeform feature. The framework can make freeform feature model be parameterization. Then, on the basis of the framework, this paper researched a validity maintenance for the freeform feature with attachment, which could keep the validity of freeform feature with attachment.