Research On Floating Raft Vibration Isolation System Considering Foundation Motion And Its Application In Underwater Vehicle

Nowadays,the underwater equipment represented by submarine is developing towards the direction of complexity,compactness and high speed.The vibration of internal equipments increasingly affects the comprehensive performance of the submarine.The vibration reduction technology for the vibration source equipment restricts the development level of the submersible.Therefore,it is of practical significance to study the vibration isolation systems inside the submarine.This paper supported by the National Natural Science Foundation of China(52075294)and the Shenzhen Natural Science Foundation of China(JCYJ2019081217081 1682),focuses on the floating raft vibration system in an underwater vehicle,the influence of the foundation motion on the vibration isolation performance of the vibration isolation system is considered,and establishes the full-degree-of-freedom dynamic model of the vibration isolation system.The influence of foundation motion and different design parameters combination of floating raft on the vibration isolation performance is analyzed,the selection criteria of design parameters of the vibration isolation system considering the moving foundation are given.Finally,the application of particle damping in floating raft vibration isolation systems is discussed.The main contents of this paper are summarized as follows:Firstly,in order to describe the motion mode of foundation of vibration isolation system in dynamic model,moving frames is established based on Moving Frame Method.Based on these frames,the motion of components of vibration isolation system is described.By calculating the connection between these frames,the full-degree-of-freedom dynamic model of the whole vibration isolation system is established.Based on this model,the analytical work of the vibration isolation system is carried out.Next,in order to study the vibration isolation performance of the vibration isolation system,this paper defines a evaluation index based on the force between components,and it is suitable for the theoretical analysis of vibration isolation performance of multi support vibration isolation system.Based on this index,this paper analyzes the influence of foundation motion and typical design parameters on the vibration isolation performance of floating raft vibration isolation system.In addition,this paper designs a floating raft vibration isolation system configuration according to the specific submarine project requirements,and verifies the effectiveness of the vibration isolation system through simulation.In the process of simulation,in order to simulate the performance of rubber isolator,the stiffness of isolator based on hyperelastic constitutive material model is discussed,and an isolator model with high linearization level was obtained.Based on the isolator model,the effectiveness of the vibration isolation system is confirmed in the simulation.According to the design parameters,the experimental model of the isolation system is manufactured,and the vibration reduction performance under rated working conditions is tested in prototype of the submersible.The results show that this vibration isolation system configuration achieves good vibration reduction effect.Finally,this paper also discusses the application of particle damping technology in floating raft vibration isolation systems.By testing a floating raft vibration isolation system with particle damper,the effect of the specification of steel balls which filled in the damper and the filling rate of steel balls on the vibration isolation performance is analyzed.The test results shows that the particle dampers have excellent vibration damping effects in a wide range of excitation frequencies and have good application prospects in the floating raft vibration isolation system.