某高強鋼輕量化副車架的動剛度優化

韋友超　周思　伍馬志

摘 要：由于前副車架通過發動機后懸置與發動機相連，為了避免結構共振和降低轟鳴聲， 提升NVH性能，必須進行副車架的動態響應分析，其中動剛度是極為重要的指標。本文以某公司SUV的前副車架為例， 采用FB780高強鋼減薄并結構優化得到第一輪輕量化模型，運用有限元軟件Optistruct對輕量化模型進行動剛度分析， 并通過調整子級零件板材的厚度分析其對動剛度的敏感性，同時結合重量敏感性得出不同板材厚度的最優組合。最終得到最優的輕量化方案，比原量產副車架減重3.8KG，減重20%，而動剛度性能指標并不降低。為乘用車前副車架的設計和優化提供了動剛度分析依據。

關鍵詞：副車架 動剛度 輕量化 敏感性 Optistruct

Dynamic Stiffness Optimization of a High-strength Steel Lightweight Subframe

Wei Youchao，Zhou Si，Wu Mazhi

Abstract：Since the front subframe is connected to the engine through the engine rear mount， to avoid structural resonance， reduce roar and improve NVH performance， the dynamic response of the subframe must be analyzed， among which dynamic stiffness is an extremely important indicator. This article takes the front sub-frame of a companys SUV as an example， uses FB780 high-strength steel to thin and optimize the structure to obtain the first round of lightweight model， use finite element software Optistruct to analyze the dynamic stiffness of the lightweight model， and adjust the sub-parts. The thickness of the plate analyzes its sensitivity to dynamic stiffness， and combines the weight sensitivity to obtain the optimal combination of different plate thicknesses. In the end， the optimal lightweight plan was obtained， which reduced the weight of 3.8KG and 20% compared with the original mass-produced sub-frame， while the dynamic stiffness performance index did not decrease. It provides a basis for dynamic stiffness analysis for the design and optimization of the passenger car's front subframe.

Key words：subframe， dynamic stiffness， lightweight， sensitivity， Optistruct