某轻型货车路试中发现其燃油箱含有一半燃油时容易发生焊点开裂、防波板脱落的现象.针对此问题,基于流固耦合系统方程对轻型货车的燃油箱利用流固耦合法进行模态和振动仿真分析.首先对不同充液比油箱进行模态仿真,通过模态计算发现:与空油箱相比,含有燃油的油箱模态频率较低,随着注油量的增加,模态频率曲线随阶数增加变的平缓.在模态分析的基础上根据国标对燃油箱振动谱的规定,重点对含有50 ％燃油的燃油箱进行了振动仿真,通过提取焊点处横向、纵向、垂向三个方向及严酷方向的应力与试验应力值对比发现,误差均在10 ％以内,验证了该分析方法的正确性.%In the road test for a light truck, it is found that the fuel tank has the phenomena of solder joint cracking and baffle plate shedding. These phenomena may occur very easily when the fuel tank is nearly 50％ filled. In this study, a fluidstructure coupling method is adopted for modal analysis and random vibration analysis of the fuel tank of the light truck. The result of modal analysis for different liquid-filling ratio of the fuel tank indicates that the modal frequency of fuel-containing tank is lower than that of the empty tank. As the oil injection increases, the modal frequency increases mildly vs. the increase of the order. On the basis of the modal analysis, the vibration of the 50 ％ filled tank is simulated and analyzed. The solder joints'stresses in the horizontal, longitudinal and vertical directions and critical direction are extracted. It is turned out that the calculation error is below 10 ％ compared with the experimental data. So, the correctness of the proposed analysis method is verified.
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