| The conceptual design of the body structure is the key to the design of the car body,which determines the overall structure of the vehicle,and is widely recognized by the automobile enterprises.The main section of the car body is a tool for the design of the body structure,and its property is important to the performance of the vehicle,which directly affects the performance of the body stiffness,strength,NVH,passive safety,etc.The optimization design of the main section for the improvement of the vehicle structure,reasonable distribution of body parts materials,weight reducement of the car body,raise of vehicle stiffness and strength,improvement of the safety and reliability of the vehicle has important practical significance.Currently,the positive concept design of car body mainly depends on the experience of engineers,which needs repeated exploratory and confirmatory test design,high labor intensity of design and long cycle.So it’s difficult to guarantee the quality of the whole body structure design,how to effectively use the body main section is the key to solving the problem.The design of the application system of the main section in the conceptual design stage of the car body has important engineering significance for guiding the design of the body structure and shortening the development cycle.The researsh mainly focuses on the main section management method and its application system development.According to the characteristics of the conceptual design stage,this paper establish a simplified geometric wire frame model of car body,and determine the 18 main sections.By using the method of rectangular simulation and polar coordinates,the main section of the car body is parameterized,the extraction method and the realization process of the main section of the car body are studied,and the calculation method of the characteristic parameters are designed.By using CAD software,the image conversion of engineering drawing is realized,and the source of main section is widened.Study on the standard methods of main section to construct the main section library in accordance with the unified standard,on the basis of this research,this paper studies the representation method of main section data,establishes the object-oriented retrieval data model of main section,using the storage form of hierarchical and characteristical to determine the storage structure,useing nearest neighbor algorithm combined with induction method to reduce the search range,match the main section attributes,accurately find the most similar main section.Finally,the modification of the main section is carried out by using the method of stiffness chain optimization and domain knowledge.According to the positive body structure concept design process and main section stiffness chain optimization analysis method,this paper put forward the stiffness chain positive concept design process driven by main section based on the research results of the car body stiffness chain design method of our team,and as a design idea,develope the body main section application system.The system integrated process can realize the design,analysis and optimization of main section on the same platform operating environment which significantly improve the design efficiency of car body.The research of this paper provides a new design tool for the body engineers,which provides a valuable reference for the development of the positive conceptual design of domestic automobile enterprises. |
