本文分析了流固耦合法和虚拟质量法两种模拟流体对结构动力学特性影响的方法,对比了两种理论的前提假设的差异。对某款车型燃油箱,分别建立了基于这两种方法的有限元模型。通过对比两种有限元模型的模态分析结果和测试结果,表明基于虚拟质量法的模态分析结果比流固耦合模态分析结果更接近实际测试。 This paper analyzes the influence of fluid-solid coupling method and virtual mass method on structural dynamics, and compares the difference between the two assumptions. For a certain type of fuel tank, the finite element model based on these two methods has been established respectively. By comparing the modal analysis results and the test results of the two finite element models, it is shown that the modal analysis results based on the virtual mass method are closer to the actual tests than the results of the fluid-solid coupling modal analysis.