Research And Development Of Parametric CAD System For Rail Train Profile

The development of urban rail transit is the focus of today's public transportation in China.In order to further improve the design level of the shape of urban rail train in China and provide powerful design tools for designers.Based on the principles and elements of urban rail train shape design,the theory of parametric CAD technology and the interactive genetic algorithm(IGA),this paper uses Rhinoceros software and Corel Draw software as the development platform to design and develop a parametric CAD system for urban rail train shape design.Through the research on the current state of urban rail train shape design and train CAD technology,combined with the problems encountered by designers in the early stage of drafting,model construction and design evaluation,the design requirements of the parametric CAD system was deeply analyzed and the shape design principles and design elements of urban rail train are summarized.The shape design of urban rail train is divided into two parts: modeling design and color design.The related design elements are summarized through the affinity diagram method(KJ method),which provides guidance for the development of the system from a design perspective,at the same time,the method of modeling the train head surface is explored,which provides technical guidance.Combined with the needs of designers in actual work,the system is divided into 2D generation tools and 3D generation tools to provide designers with auxiliary paths from different angles.The 3D modeling software Rhinoceros and the 2D drawing software Corel Draw were selected as the development platform.Based on Rhino Common for the secondary development of Rhinoceros,the whole surface design of rail train car body design,characteristic line and surface design,standard parts design and program evaluation function module were designed;Based on the VBA language for the secondary development of Corel Draw,three functional modules were designed,including 3D model rapid generation,train front plan generation,and train side plan generation.The developed system is rich in functions,simple in operation and good in humanmachine interface.The system greatly reduces the workload of the modeling designer,assists the repetitive and complicated design work with the help of computers,improves product design efficiency,shortens the research and development cycle.The reasonable division of labor based on designers and intelligent technology expands the breadth of search for concept solutions and improves design efficiency.