船舶阻抗失配基座对平面弯曲波传递的阻抑特性

研究了船舶阻抗失配基座对平面弯曲波传递的阻抑特性.基于波动理论,根据不均质结构中波型转换、阻抗特性,推导并给出了振动波入射不同连接形式的船舶基座结构的透声系数及隔声量公式,归纳了隔振性能随基座板架厚度比及频率变化规律,讨论了基座连接结构处板架固定方式对隔振性能的影响.在理论分析基础上,构造含阻振质量的阻抗失配基座.数值结果表明阻抗失配基座显著增大了基座的输入机械阻抗,加剧了振动波在船体板架中的波形转换、散射和反射,显著提高了舰船基座结构的隔振效果.

Attenuation of the Flexural Wave Transmission Through Impedance Mismatch Hull Base

The characteristics of impedance mismatch hull base attenuating propagation of plane bending waves are researched on the basis of wave theory.The sound transmission coefficient and transmission loss of different junction bases incident by vibration wave are deduced according to wave conversion and impedance attribute in non-homogeneous structures,and the regularity of vibration isolation performance with the base plates thickness ratio and frequency is also given.Furthermore,the influence of plates fixed form at base junction to the sound isolation performance is discussed.After theoretical analysis,the blocking masses are introduced to impedance mismatch of hull base.The numerical calculation results show that the vibration isolation performance of impedance mismatch hull base is increased notably because the impedance mismatch base enhances the input mechanical resistance of base structure.Impedance mismatch base also aggravates vibration wave conversion,scattering and reflection in hull plates.