某乘用车燃油箱在行驶过程中，由于路面颠簸产生的振动导致油液在燃油箱体内晃动，并且油液晃动 主要以上下的周期性形式呈现，燃油箱体上很容易产生裂纹。为了探究油液在周期载荷作用下对燃油箱产生 的影响，以振动耐久性试验为基础，利用有限元分析软件对燃油箱进行模态及谐响应分析。通过此分析方法得 出油箱的固有特性，经过谐响应分析进行验证并计算得出位移频响和应力频响结果，再通过位移频率响应和 应力频率响应找到油箱结构在实际载荷作用下的危险区域判断是否满足振动耐久性使用要求。应用此分析方 法可以更快的找到油箱结构在周期性载荷作用下的薄弱点，对燃油箱由外载荷振动引起的安全问题起到预测 和防范作用，并对油箱的正向设计提供理论依据，节省设计周期，降低生产成本。

During the driving process of the fuel tank of a passenger car, the vibration caused by the road bumps causes the oil to shake in the fuel tank, and the oil shake is mainly in the periodic up-and-down form, which is easy to produce cracks on the fuel tank. In order to explore the influence of oil on the fuel tank under periodic load, the modal and harmonic response analysis of the fuel tank is carried out using finite element analysis software based on the vibration durability test. The inherent characteristics of the fuel tank are obtained through this analysis method, and the displacement frequency response and stress frequency response results are verified and calculated through harmonic response analysis. The risk area of the fuel tank structure under the actual load is found through displacement frequency response and stress frequency response to determine whether it meets the vibration durability requirements. This analysis method can quickly find the weak points of the fuel tank structure under periodic load, predict and prevent the safety problems caused by external load vibration of the fuel tank; it will provide theoretical basis for the forward design of the fuel tank, shorten the design cycle and reduce the production cost.