双层圆柱壳舷间振动传递及控制研究

Vibration isolation calculation and control between double cylindrical shell

为研究水中隔振特性,基于FEM/AML技术并采用“双层壳方法”,建立内壳充液且舷间由弹簧连接的有限长双层圆柱壳模型。通过与实体网格法进行对比,验证了“双层壳方法”的可靠性。研究水介质和弹簧对隔振特性的影响并提出一种水中隔振装置,结果表明:舱内水介质和舷外水介质会降低外壳的固有频率;舷外水介质降低了外壳的振动幅值且在低频会增大壳体的辐射声功率;舷间水介质发生“振动短路”,降低了隔振器的隔振性能;设计的气囊与隔振器相结合的水中隔振装置可有效提升隔振性能,0~500 Hz范围内的均方振速总级可减小3 dB,辐射声功率总级可减小10 dB。

In order to study the vibration isolation characteristics in water, a finite length double-layer cylindrical shell model was established based on FEM/AML technology and double shell method, in which the inner shell is filled with liquid and the inner shell and the outter shell is connected by springs. Compared with the solid mesh method, the reliability of the "double shell method" is verified. The influence of water medium and spring on vibration isolation characteristics is studied, and an underwater vibration isolation device is proposed. The results show that:the natural frequency of the outter shell will be reduced by cabin water medium and outboard water medium.The vibration amplitude of the outter shell will be reduced by the outboard water medium, and the radiated sound power of the shell will be increased at low frequency by the outboard water medium.The vibration short circuit of water medium between shells reduces the vibration isolation performance of vibration isolator.The vibration isolation performance of the underwater vibration isolation device with the combination of air bag and vibration isolator can be effectively improved. The total level of mean square velocity in the range of0~500 Hz can be reduced by 3 dB, and the total level of radiated sound power can be reduced by 10 dB.