Research On Feature-based Rapid Modeling For Aircraft Stringer Parts

Stringers are important longitudinal components in the aircraft structures. Thay are widely used in the manufacturing of fuselage and aerofoil structures. Therefore, the quality of aircraft stringer modeling can directly impact the comprehensive quality and cycle of aircraft structural design. Currently, the feature-based specialized integrated modeling solution for stringers is unavailable in the traditional aircraft stringer design process. The design process and modeling method are irregular. Stringer model cannot be driven by parameters and its adaptability performance for assembly environment is comparatively poor. The relevant design knowledge and Standards have not been effectively integrated in the design process, which cause amount of extra workload for parameter checking, equation converting and manual inputting. It increases the modeling burden on the shoulders of designers, wastes the energy, which was supposed to be spent on innovative design, now on the repeated work and further decreases the efficiency of stringer design and makes the quality of model worse. In order to refine those drawbacks above, a feature-based rapid modeling technology was researched. On the basis of CATIA V5 R18 platform, with the CATIA secondary development toolkits of CAA/RADE and by the programming language of VS2005 C++, the rapid modeling software system for aircraft stringer structures was development in the end. The main research content of this thesis includes:(1) Research on the classification of manufacturing feature-based aircraft stringer structures and normalized feature modeling technology. Establish the parametric models of aircraft stringer structures by using the parametric design technology, and scheme the unified design process for aircraft stringer parts after the analysis of design plan.(2) Research the parametric describing for the typical aircraft stringer features, and build the mathematic conversion relationship between the feature geometric parameters and user design parameters by equations. Then research the intelligent calculation technology for the geometric parameters of typical features on the basis of parametric describing method. Propose key algorithms to realize the intelligent solving for feature geometric parameters of stringer structures, in order to guarantee the information integrity during the transmission from design knowledge to geometric model.(3) Establish the mapping structural between the stringer structure features and relevant design knowledge according to the characteristics of them. Analyze the manners for stringer parts design knowledge acquisition and the technological methods for knowledge embedding and knowledge management. And build the feature-knowledge mixed feature templates library to provide both knowledge support and model support for the rapid responding of aircraft stringer part modeling.(4) Build the system framework of the rapid modeling software for the feature-based aircraft stringer structural parts. Evaluate the advantages and disadvantages of different CATIA secondary development toolkits. And on the basis of CATIA V5 R18 Platform, with the toolkits of CAA/RADE R18, and by using programming language of VS2005 C++, the feature-based rapid modeling software for aircraft stringer parts was developed in the end.