基于隐式参数化模型的白车身轻量化设计

摘要

本文在白车身概念设计阶段引入"CAE驱动设计"的思想,采用SFE-CONCEPT建立了某轿车白车身隐式全参数化模型,通过与经验证的有限元模型进行性能分析对比,验证了所建参数化白车身模型的有效性.采用逐步优化方法,结合白车身性能匹配补充轻量化设计的思想,在最大限度地满足白车身静、动态各项性能要求的前提下,获得白车身轻量化设计方案.优化前后白车身性能对比结果表明,在白车身弯曲和扭转刚度变化不大(分别下降0.2％和0.6％)情况下,车身整体长、宽和高分别增加了15,13和9mm,车身1阶弯曲和1阶扭转模态频率分别提高了5.6％和9.2％,车身质量减轻了19.9kg,轻量率达5.76％,取得了明显的轻量化效果.%In this paper, the idea of "CAE driven design" is introduced in the concept-design phase of body-in-white ( BIW) , an implicit parametric model for the BIW of a car is built by using SFE-CONCEPT, and the effectiveness of the model is validated by performance comparison with finite element model verified. A step-by-step optimization technique is adopted, combining with BIW performance matching and supplemented by the idea of light weigh design, to find the light weight design scheme of BIW on the premise of meeting all the static and dynamic performances of BIW to the maximum extent. The results of comparison between BIW performances before and after optimization show that with the little changes in bending stiffness and torsional stiffness ( lowering by 0. 2％ and 0. 6％ respectively) , the length, width and height of car body increase by 15mm, 13mm and 9mm respectively, the first order bending and torsional mode frequencies rise by 5. 6％ and 9. 2％ respectively, and the mass of car body reduces by 19. 9kg with a lightweighting rate of 5. 76％, achieving an apparent lightweighting results.