Research On Machining Feature Recognition And MBD Modeling Of Aluminum Alloy Train Body Parts

Aluminum alloy train body components are important load-bearing parts of high-speed trains,with a large number features and complex structures.In order to solve the problems of long machining preparation cycle and low production efficiency of manual programming,it is imperative to introduce automatic programming technology,and the core technology of automatic programming is machining feature recognition and MBD(Model Based Definition)model construction technology,therefore,this paper does the following research on machining feature recognition and MBD model construction for train body components:(1)Related technologies of train body components.From the entity representation of 3D model and the classification of generalized features,this paper analyzes the types and structural features of machining features of train body components,and further classify all features into single features and intersecting features;combined with the graph-based recognition methods,an expanded concept related to feature recognition of train body parts is proposed,discusses the module definition based on MBD and related theories,it provides theoretical support for subsequent feature recognition and MBD model construction.(2)Propose machining feature recognition method for train body components.In view of the structure and distribution characteristics of processing features of train body components,a graph-based method is adopted to construct the overall expanded attribute adjacency graph of the components,and a step-by-step feature search algorithm based on feature extraction surface and feature boundary ring is proposed,it can realize the overall extraction of concave and convex features.Then,a feature matching algorithm based on node degree sorting and matrix similar row matching is designed to determine the specific feature type;towards the complex intersection features,the corresponding recognition strategy is designed to process the intersecting features and then determine their specific types,then the machining features can be accurately recognized.(3)Propose MBD model construction method for machining features of train body components.Combining the geometric and non-geometric information of machining features,a multi-level MBD expression model of machining features is designed;and the information of technical requirements existing in the form of 3D annotation on the solid model is extracted and integrated with the corresponding feature geometric elements to realize the construction of the model;Combining database technology to design data storage structure corresponding to the expression model,it can ensure the efficient transfer of model information between systems.(4)System development and verification.Combining the method of machining feature recognition and MBD model building,using the software secondary development tool,the machining feature recognition and MBD model building prototype system oriented to train body components is built,and the research method is validated by using actual train body components as input.The proposed method provides an effective solution for realizing the digital and automatic machining of train body components,reduces the preparation time and improving the production efficiency.