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• Vibration transmission mechanisms of the shell with immersed elastic connections are studied. • The forced vibration test is conducted on the double-layer shell with six immersed isolators. • An analytical approach is proposed to predict the vibration response of the double-layer shell. • The vibration test provides benchmark experimental results for future studies. • The energy transmission is quantitatively partitioned with respect to elastic connection stiffness. This paper investigates vibration transmission characteristics of the double-layer cylindrical shell with fully immersed elastic connections through experimental and analytical approaches. A test sample of the double-layer cylindrical shell connected by six vibration isolators is firstly manufactured and a forced vibration test is done with fully immersed interlayer. Meanwhile, a novel analytical approach is developed to calculate vibration responses of an unequal double-layer cylindrical shell with fully immersed elastic connections. The substructure receptance method and wave propagation method are combined in the coupling theoretical model. Springs are utilized to simulate elastic connections, that are considered as substructures. By comparing the achieved analytical and experimental vibration responses, good agreements are gained and the two approaches are demonstrated. Then the transmission characteristics are gradually analyzed with respect to the double-layer shell with elastic connections, double-layer shell with interlayer fluid and double-layer shell with fully immersed elastic connections. It is found that the interlayer water between the inner and outer shells plays a "short-circuit" role in vibration transmission, which greatly reduces the isolation performance of vibration isolators. Nevertheless, the fully immersed isolators with small stiffness still have the non-ignorable vibration isolation effect compared with the case of rigid connection. [ABSTRACT FROM AUTHOR]

This paper aims to clarify the behaviour and mechanism of electromagnetic vibration in long sheet secondary tubular linear induction motors (LSS‐TLIMs). Firstly, the spatial and temporal characteristics of electromagnetic force acting in the stator are analysed. Secondly, based on the wave propagation method, an analytical model is established to calculate the vibration response of the stator, which is simplified as a finite cylindrical shell. The accuracy of the proposed model, as well as the rationality of the simplification, are verified by 3D FEM simulation. It is indicated that the electromagnetic vibration response of LSS‐TLIMs mainly depends on the "axial breathing mode" (ABM) and corresponding "modal participation factor". Moreover, the influences of the spatial distribution of electromagnetic force and the structural dimensions on the vibration are investigated. Finally, the "static vibration test" is performed to validate the above analysis. It is concluded that, compared with a rotary motor, the low‐frequency vibration of LSS‐TLIMs can be easily controlled since the natural frequency of ABMs tends to be much higher than that of the circumferential mode. [ABSTRACT FROM AUTHOR]