Research on the influence of acoustic short circuit fault of air spring isolator on ship floating raft isolation system

Air spring isolator is the crucial component of ship floating raft isolation system. However, due to various factors such as manufacturing errors and installation conditions of air spring isolators, abnormal contacts cannot be avoided in the internal limiters of air spring isolator, resulting in the acoustic short circuit fault. This leads to a significant decrease in isolation effectiveness. To address this issue, experiments on the acoustic short circuit fault of air spring isolators are conducted, and the experimental results are analysed. Then the causes behind the phenomena and results of the acoustic short circuit experiments are further elucidated through finite element simulations and mathematical theory analysis. The research results indicate that the acoustic short circuit of air spring isolators affects the isolation effectiveness. The more severe the acoustic short circuit fault, the greater its impact on the isolation effectiveness, particularly in the low-frequency isolation component. This is because, during the acoustic short circuit of air spring isolators, the rubber part of the internal limiter comes into contact, causing an increase in the stiffness of the air spring support, thereby resulting in an increase in the modal frequency of the isolation device and consequently severely impacting the low-frequency isolation effectiveness.