Structural-Acoustic design to depress line spectrum of radiation noise from double cylindrical ring stiffened shell

In order to reduce line spectrum of radiation noise from double cylindrical ring stiffened shell, structureacoustic design was done by the way of controlling inner shell's vibration response and attenuating wave transmissibility between two shells. Mechanical impedance theory was used to analyze mechanism of controlling modal response amplitude of ring-stiffened cylindrical shell The characteristic of radial modal mechanical impedance of the ring was analyzed Based on impedance mismatch and wave conversion a type of impedance enhancement rib was summed up and the vibration wave attenuation characteristic was analyzed. Considering the stiffness and damping of rib plate, metal rubber laminated rib-plate was proposed by applying damping vibration attenuation technology. Combined with specific calculation examples, the characteristics of vibration and sound radiation were analyzed. The results showed that the proposed double cylindrical ring stiffened shell could reduce radiation noise line spectrum effectively, the line spectrum of radiation pressure averagely decreased by 6.6 dB in analysis frequency band. It had a better engineering value and application prospect