增压充液贮箱振动特性的理论与实验

Theory and experiment for vibration analysis of liquid-filled tank with internal pressure

结合理论与实验方法研究了增压充液贮箱的振动特性。采用弹性薄壳理论和速度势理论建立了增压充液贮箱的动力学方程组。考虑内部加压对贮箱振动的影响,引入内外压差作用项;考虑弹性壳体与液体间的耦合作用,给出液体动压的表达式。采用经典边界值法计算出贮箱振动频率;设计贮箱模型进行固有振动频率的实验测试。所得计算结果与实验值一致,均表明充液使贮箱振动频率下降,而内部加压使贮箱振动频率增加。进一步分析,得到增压充液贮箱振动频率随波数、贮箱内压、充液密度、贮箱几何参数和材料刚度等因素的变化规律。

A theoretical and experimental investigation of the vibration characteristics of fluid-filled tank with internal pressure is presented.The dynamic equations of vibration are based on the elastic mechanics and velocity potential theory.The form related to the difference of pressure inside and outside was given by analysis of its effects on the tank.Also the form related to the solid-fluid interaction was given by analysis of its effects.The classic boundary-value approach was used here to calculate the natural frequencies of the tank.A modal experiment about vibration characteristics of fluid-filled tank with internal pressure was conducted,and the frequencies were measured.Results of theoretical calculation agree with the experimental data,which indicates that the frequencies of the tank decrease when filled with liquid,but they increases with internal pressure,compared with that of the empty tank.Further analysis of the results shows the effects of factors,such as the wave number,internal pressure,fluid density,structural geometric parameters and flexural rigidity of the tank on the dynamical behaviors.