Analysis of Sound Radiation from Double-layer Cylindrical Shells Connected by a New Type of Joint-structure

The vibro-acoustic design of the joint-structure in double-layer cylindrical shells was done from the viewpoint of attenuating vibration-wave transmission.Applying the theory of vibration reduction and isolation and the Snowdon’s isolator model,a new rubber-mass type joint-structure connected in the cylindrical shells was proposed.This structure is approximately a mass-spring-damping vibration reduction system with the characteristics of high elasticity and damping.Then,the vibro-acoustic characteristics of a double-layer cylindrical shell were analyzed numerically.Finally the effect of stiffness,damping and additional mass of the joint-structure on the vibro-acoustic performance of the double-layer cylindrical shell was discussed.The results show that the new-type connection can depress vibration and sound radiation effectively,the variation of stiffness,damping and additional mass of the joint-structure have a larger influence on the vibration attenuation and noise reduction efficiency.The research results can become a reference for submarine acoustic stealth design.