Research On Generation Method Of Casting Blanks For Aerospace Structures Driven By MBD

Complex aerospace structural parts are generally processed from cast blanks,and the method of forming blanks directly affects the processing efficiency and processing cost of the parts.It is very important to obtain efficient and economical blanks.For the selection of the casting blank model,it is necessary to consider the manufacturing process,and the three-dimensional design model reversely generates the blank model.Complex aerospace structural parts have many characteristics of processing features and complex manufacturing processes,which brings problems to the casting blank generation process.The selection of the blank model of such aerospace structural parts generally requires the craftsman to analyze the characteristics of the parts,consider the possible reduction route and the process reduction method to determine the appropriate blank model.At present,from the MBD design model to the selection of the blank model,the following problems exist: First,the process personnel cannot effectively utilize the information problem on the MBD design model,so that the design information and characteristics of each feature in the blank generation process are processed.Resource information cannot be effectively combined,and processing resources are mostly manually selected.Second,the rough reduction process route needs to be manually determined according to experience,and the intermediate process model of the blank reduction has the problem of repeated modeling,resulting in long blank selection period and low efficiency.In response to the above problems,this paper has done the following research:(1)For the MBD design model In the process of constructing the traditional reduction feature model,the information utilization efficiency is low and the processing resources of the feature cannot be quickly selected.This paper proposes a method for constructing MBD reduction features for aerospace structural components.On the basis of the recognition of the processing features and the extraction of the annotation information,a process knowledge base of processing resources is established,and the model information of the restored features is expressed using the knowledge map,and stored in the graph knowledge base,and the reduction features are selected based on the decision tree algorithm.The associated processing method and the processing equipment information based on the knowledge base case were selected,and the MBD reduction feature model was finally successfully constructed.(2)For the rough reduction process route,the intermediate process model that needs manual formulation and blank reduction needs to be repeatedly modeled.This paper proposes a three-dimensional blank model generation method,which is studied from two aspects: process reduction route and feature reduction method.In terms of process route reduction,with the optimization of processing cost and processing efficiency,a genetic algorithm for solving the blank reduction route is proposed.In the aspect of feature reduction method,the single feature and the reduction method of intersecting features are studied.The feature filling algorithm is used to restore these features.According to the process reduction route,different features are successively restored to generate a threedimensional blank model.The example verification shows that the genetic algorithm can effectively confirm the process reduction route,and the feature filling algorithm can realize the reduction of through holes,cavities,blind holes,through cavities,grooves,bosses and partial intersecting features.(3)According to the actual production needs of the enterprise,a set of casting blank model generation system for aerospace structural parts was developed.The blank model generation system can automatically generate processing resources through feature geometry and feature annotation information,determine the process reduction route by MBD reduction feature information,and automatically restore the restoration features according to the process reduction route.The case study of aerospace structural parts shows that this system can meet the requirements of rapid and effective generation of blank models.