概念设计阶段铝合金后副车架轻量化设计

Lightweight Design of Aluminum Rear Subframe in Conceptual Design Stage

本文重点探讨了铝合金后副车架性能目标的制定与轻量化设计方法。首先采用正向设计与竞品分析相结合的方法制定了铝合金后副车架的质量、模态、静刚度与强度等目标。然后为得到后副车架的骨架并轻量化,引进ICM混合建模方法,通过对后副车架传力路径的识别,对其进行拓扑优化,去除冗余材料,得到数学模型。选择参数化副车架的12个形状变量作为多学科优化轻量化设计变量,得到满足目标要求的最优形状。轻量化后质量减小1.84 kg,约减轻了7.4%;1阶弯曲模态提高10.2 Hz,约上升了4.5%。硬点静刚度与强度的分析结果也表明了该方法快速可靠,具有良好的工程应用前景。

The formulation of performance targets and the lightweight design method of aluminum alloy rear subframe are emphatically investigated in this paper.Firstly,a method combining forward design and competitive product analysis is adopted to determine the performance targets of aluminum alloy rear subframe,including mass,modal frequencies,static stiffness and strength etc.Then the ICM hybrid modeling method is introduced to obtain the skeleton of rear subframe and reduce its weight.Based on identifying the force transmission path of rear subframe,topology optimization is performed,redundant material is removed and the mathematical model is obtained.Twelve shape variables of parameterized subframe are selected as the lightweight design variables for multidisciplinary optimization to obtain the optimal shape meeting target requirements.After lightweighting,the mass reduces by 1.84 kg with a mass reduction rate of 7.4%,and the 1st-order bending frequency increases by 10.2 Hz,meaning a 4.5%of enhancement.The results of hard point static stiffness and strength analysis also show that the method is fast and reliable,with a good prospect of engineering application.