基于约束Delaunay三角剖分的筋特征识别与构建算法

为识别飞机结构件中的筋特征,提出一种基于Delaunay三角剖分的识别与构建算法。首先,根据飞机结构件腹板和平顶筋加工方式的不同以及二者几何上的相似性,引入广义腹板概念表示腹板面和平顶筋,并建立筋的表示模型;其次,利用约束Delaunay三角剖分算法,剖分广义腹板面,进行平顶筋面和腹板面的识别与区分,并提取平顶筋面的中轴线;最后,利用中轴线拆分平顶筋并将斜顶筋作为广义腹板的子特征进行识别与构建。实例结果表明,该算法是正确和有效的。

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.