考虑冲压成形历史的轿车前纵梁总成碰撞仿真

Crashworthiness Simulation of Automobile Front Rail Assembly with Consideration of Sheet Forming History

以轿车前纵梁总成为对象,将冲压成形引起的板料厚度减薄、残余应力和等效塑性应变映射到碰撞仿真模型中,详细分析这些因素对零件碰撞过程中能量吸收和碰撞力的影响规律,并从兼顾计算精度和计算效率的角度对影响仿真精度的主要因素进行了分析.结果表明:与忽略冲压成形历史的碰撞仿真结果相比,引入冲压成形历史的碰撞仿真所得内能增大,碰撞力峰值增大及峰值出现时间延后;厚度变化对零件的吸能特性影响显著,残余应力和塑性应变对碰撞力的影响显著.

The thickness thinning,residual stress and effective plastic strain resulted from sheet metal forming process were introduced into the crashworthiness simulation of a front side rail assembly in this work.Influences of these forming effects on the energy absorption and reaction force were analyzed in detail.The main factors determining the calculation precision and its efficiency were discussed.Results show that the internal energy with a consideration of the forming history is larger than that neglecting the forming history.And the peak force is larger and late.Among the thickness,the residual stress and the effective plastic strain,the thickness is the most significant factor for the energy absorption and the residual stress and effective plastic strain are important factors for the reaction force.