桨-轴-艇纵向耦合振动机理研究

Study on longitudinal coupling vibration mechanism of propeller-shaft-hull system

桨-轴-艇结构耦合振动是影响潜艇振动和水下声辐射的重要因素。本文建立了桨-轴子系统和桨-轴-艇耦合结构的数学模型,从动力学分析角度推导了耦合结构振动与子结构各振动物理量之间的关系;通过有限元法对理论分析结果进行了验证,并研究了桨-轴-艇耦合结构水下声辐射频谱与子结构典型模态的关系。有限元数值计算结果与理论分析均表明,桨-轴-艇结构耦合振动导致原耦合结构的模态频率发生偏移,从数学的角度揭示了桨-轴-艇产生纵向耦合振动的根本原因,并给出了耦合结构水下声辐射与子结构典型模态之间的对应关系。

The coupling vibration of propeller-shaft-hull structure is an important factor which influences the vibration and underwater acoustic radiation of submarines. Mathematical model of the propeller-shaft subsystem and propeller-shaft-hull coupling structure is established and the relationship between coupling structure vibration and each physical quantity of substructure is derived based on the dynamic analysis. The result by finite element method is validated and the relationship between underwater acoustic radiation of propeller-shaft-hull coupling structure and typical modes of substructure is studied. The FEM results and theoretical analysis results show that the main reason of propeller-shaft-hull coupling is the modal frequency being changed, which validates the correctness of theoretical analysis, reveals the fundamental reason of longitudinal coupling vibration and give out the corresponding relationship between underwater acoustic radiation of coupling structure and typical modes of substructure.