Establishment And Application Of Car Body Cross-section Of The Database

This article comes from Major projects in Jilin Province Science and TechnologyDepartment of FAW Technology Center supporting the project---passenger car collisionconceptual modeling and optimization analysis, to create a typical passenger car sectiongeometry and mechanical properties of the database is one of major project task, and toapply it.Car is a special member of the beam and the various forms of the cover body areconnected together by welding, where in the body plays a major role in the load beam tosupport the entire vehicle body. The body stiffness is determined by the characteristics ofthe body section of the beam, therefore, researching the body section beam has a importantengineering significance.Studying the geometric characteristics of the car body and mechanical properties of thebeam cross-section, and organize data to construct detailed beam section database of Carbody, has completed a workload of nine cars. But the establishment of cross-sectiondatabase is not only a query tools and reference materials, but using of rules of the beamcross-sectional shape and the mechanical properties of cross-section of beam can beparameterized,to do the design parameters to optimize the beam section, to improve theperformance of the body.First, maked a detailed description of the car body structure, including the front, theside frames, the bottom and the back of the car. Then intercepted the beam section line inthe finite element software HyperMesh, generated beam section in HyperBeam, countedbeams sectional data and built a database of car body beam section.Secondly, based on the theory of finite element modeling,according to the C-car bodydetailed finite element model, extracted beam section from C-car body section of thedatabase, re-simulated divided beam element with cross-section mechanical properties of The body of the beam area in detailed finite element model of the C-car body, buildingC-car beam shell mixed finite element model, then to do the torsional model and modalanalysis, comparison with the original model, verify the reasonableness of C-car hybridfinite element model of the body.Then, based on the sensitivity analysis of modal theory, with a cross-sectional momentof inertia and cross-sectional area of the beam element of design variables, overall qualityof the body as a constraint, one order torsional frequency of optimization goals,to dosensitivity analysis, and record the value of the sensitivity, determine the sensitivity of thehigh beam.Finally, on the more sensitive beam element, find the corresponding area on thedetailed finite element model. These areas is relatively weak with first-order torsionalfrequency region on the body, which is optimized region, establishing Domians on theseareas for structural shape optimization analysis.