Research On Characteristics Of Two-Stage Vibration Isolation System Based On Statistical Energy Analysis

Two-stage vibration isolation system has been widely used in fields of ships, mechanical, vehicle and so on, due to its good effect on vibration isolation and noise reduction. Evidences accumulated show that the research on isolation characteristics of two-stage vibration isolation system and analyzing the effect of each parameter on isolation effect are of great significance to guide the two-stage vibration isolation system design.In this thesis, statistical energy analysis(SEA) modeling method of two-stage vibration isolation system is studied using the basic theory of SEA. The vibration isolator is divided into an individual subsystem,which makes the non-conservatively coupled system equivalent to the conservatively coupled system,so that the classical statistical energy equation is suitable for it,and makes it convenient to analyze in the commercialized software AutoSEA. The SEA model of flat suspended two-stage vibration isolation system is established to predict the vibration level difference and power flow transfer ratio, the results comparison between simulating and experiment shows that the simulating results agree well with the experimental results at medium and high frequency bands, which indicates that the SEA model of flat two-stage vibration isolation system is credible and the SEA modeling method of two-stage vibration isolation system has practical value in engineering.The SEA model of lateral suspended two-stage vibration isolation system is established based on the verification of SEA modeling method of two-stage vibration isolation system, and its power flow is further studied. Then, the lateral excitation and lateral vibration characteristics are analyze. The results show that increasing damping of floating raft and base, adding the thickness of base or decreasing the rigidity of vibration isolator can enhance isolation effect, which lay a foundation to optimization design of two-stage vibration isolation system.The experimental methods of SEA parameters of two-stage vibration isolation system is studied, then damping loss factor and coupling loss factor of each subsystem are acquired through experiments. Vibration level difference and power flow transfer ratio of two-stage vibration isolation system were measured experimentally, which verify the correctness of simulation results.