Extendible classification of design and manufacturing features

This paper discusses three different issues in feature classification. It proposes a complete taxonomy to cater for prismatic and rotational features which can be positive or negative. It also suggests a feature definition that makes it feasible for the feature library to be extendible without additional programming effort. A unique code is given to each feature so as to avoid redundancy and ensure consistency of labelling the feature faces. This labelling is achieved by a novel formalisation method based on a newly found graph-theoretical property of a B-rep model. Results for one of the several components investigated are included.