Algorithm for recognizing and constructing rib feature based on constrained Delaunay triangulation

In order to recognize the rib feature in aircraft structural parts, a recognition and construction algorithm based on the constrained Delaunay triangulation is presented. First, according to the different machining methods between the real bottom plane and the flat rib as well as the similar geometric characters of these two features, the concept of generalized bottom plane is introduced to represent the real bottom plane and the flat rib. Moreover, a representation model of the rib feature is established for further recognition and construction. Second, the constrained Delaunay triangulation method is adopted to decompose the generalized bottom plane, recognize and distinguish it as the flat rib or bottom plane, and then extract the medial axis of the flat rib. Finally, the flat rib is divided as per the medial axis while the declining rib is recognized and constructed as a sub-feature of the generalized bottom plane. The validity and efficiency of this algorithm have been verified through examples.