A New Approach for Naming and Identifying Topological Entities

One of the fundamental issues based on history parametric feature modeling is how to name and identify topological entities. And the essence of this issue is to maintain the implied design intent. Firstly, we define the directed isoparametric lines (DIL) on faces, and propose a new approach taking face as the core to name the referenced topological entities. Based on the DIL-based face-face relationship (FFR), the approach is implemented by using the local topological information as well as geometrical characteristics. Secondly, in order to identify a referenced topological entity, The adjacent faces of the entity are divided into active face set and inactive face set, and the implied design intent is captured based on subset relationship criterion. The proposed approach has been tested by a number of examples, which shows the approach can deal with the case of topology variation more effectively.