考虑冲压影响的燃油箱模态分析及振动耐久性研究

Modal Analysis and Vibration Durability Considering Forming Technology Effect for Fuel Tank

针对金属燃油箱冲压过程引起不均匀塑性变形和厚度变化,研究了冲压结果对结构振动耐久性的影响。首先,采用有限元方法对燃油箱进行了模态分析,研究冲压结果对模型频率的影响;然后,进行30Hz激励下的谐响应分析,对比了燃油箱考虑冲压影响的应力响应,并根据计算结果进行了疲劳性能评价;最后,按照GB 18296-2001对燃油箱进行了振动耐久性能试验,试验过程中燃油箱在冲压减薄部位先后出现开裂现象。试验与仿真结果对比表明:采用考虑冲压影响的模态分析方法能够更为准确地评价结构振动耐久性。

In studying metal fuel tank vibration durability, the effects of its uneven plastic deformation and wall thickness difference resulted from stamp forming technology must be considered. Firstly, Fuel tank modal analysis was conducted using FE method to examine effect of stamping on its vibration frequency. Secondly, the harmonic response analysis under 30 Hz exciting frequency was performed and examining variation of the stress response after considering the stamping effect, and the calculated results were used to evaluate fatigue characteristics. Finally, according to GB 18296--2001, fuel tank vibration durability test was performed and some cracks were found in thinned regions. The results demonstrate that the modal anal- ysis method considering stamping effect can more accurately evaluate vibration durability of the fuel tank.