一体化压铸铝合金前机舱轻量化设计与优化

Lightweight Design and Optimization of Integrated Die Casting Aluminum Alloy Front Cabin

当前汽车行业对低碳化和轻量化的需求日益增长,新型一体化压铸技术应用于车身,能够实现质量、生产成本和周期的下降,并减少碳排放,成为各大汽车主机厂商争相研究热点。本文将某乘用车传统钢制车身前端机舱结构替换成一体化压铸件,对铝合金一体化前机舱进行了轻量化设计。通过SIMP法对前舱进行拓扑优化得到了最优刚度载荷路径,考虑前舱可铸造性对筋的拔模方向、厚度尺寸和位置分布进行设计。根据C-NCAP 2021进行正面碰撞仿真,通过田口实验设计方法与响应面优化改善了一体化压铸车身的耐撞性,并对优化后的白车身性能进行了仿真分析。与传统方案相比,一体化方案的质量减轻13.9%,白车身弯曲刚度提升9.7%,1阶模态达到要求。本文研究对后续一体化车身结构的平台化设计与工程应用具有指导意义。

The requirement of low carbon and lightweight in the auto industry is growing now.The new mega-casting technology applied on vehicle body can better achieve weight,cost and emission reduction,and has become spotlight to automobile manufacturers.In this paper,the traditional steel front compartment of passenger car body is replaced by integrated die casting part,and lightweight design on the aluminum alloy integrated front engine compartment is conducted.The optimal load path for stiffness is obtained through topology optimization of the front cabin by SIMP method.Considering the castability of the front cabin,the draft direction,thickness size and position distribution of the ribs are designed.Frontal impact simulation is conducted according to C-NCAP2021 and the im-pact resistance of the integrated die cast body is improved through Taguchi experimental design method and re-sponse surface optimization.Simulation analysis is conducted on the optimized performance of the white body.Com-pared with the traditional scheme,the weight of the optimal design is reduced by 13.9%,with the bending stiffness of the BIW increased by 9.7%,and the first modal meets the requirements.The research in this paper is meaningful for the platform design and industrialized application of integrated die casting car body structure in the future.