Research On The Prediction Of Vibration Isolation Effect Of Marine Floating Raft And The Influence Of Its Parameters

The ocean is the treasure house of natural resources,with the development of the world science and technology,the competition in the marine field is becoming more and more an important focus of the comprehensive national power competition between countries,the development of the ship industry is an important part of the development and utilization of marine resources.The vibration and noise of the ship is an important factor affecting its combat effectiveness and vitality,and the vibration of hull equipment is an important source of hull vibration.The common method to reduce equipment vibration is vibration isolation device technology,of which the floating raft vibration isolation technology is the key research area of the current hull vibration and noise reduction.How to accurately forecast and improve the vibration isolation effect of floating raft vibration isolation system is an important research content of current floating raft vibration isolation technology.In this paper,the solid modeling of vibration isolator is used to reduce the errors in the prediction of vibration isolation effect in the high frequency band.The solid model of JSD-85 rubber vibration isolator is established to verify its static deformation term and installation frequency term;then the solid model of BE-25 rubber vibration isolator is established to verify its input velocity impedance.These two checks are used to verify the correctness of the solid modeling approach.The model of the middle raft of the floating raft vibration isolation system is established,and the model of the JSD-85 rubber vibration isolator is assembled together to establish a complete model of the floating raft vibration isolation system,which is imported into the ANSYS Workbench software.Through the harmonic response analysis module,the acceleration level dropout value is calculated,and the vibration isolation effect of the floating raft vibration isolation system is reasonably predicted according to the calculation results for three different equipment quantities and force conditions.This paper continues to discuss the vibration isolation effect of the floating raft vibration isolation system under nine different arrangements of lower vibration isolators,and analyzes the effect of different numbers of vibration isolators in the transverse and longitudinal directions and with or without intermediate supports on the vibration isolation effect of the floating raft,so as to provide a basis for selecting a suitable vibration isolator arrangement in different frequency bands to improve the vibration isolation effect of the floating raft.The raft structure of the floating raft vibration isolation system is optimized and designed in terms of the height of the intermediate raft body,the structural form of the raft web and the overall structural style of the raft body.Finally,the simplified problem of the vibration isolator is further explored,i.e.,solving the variable parameters of the simplified two-node spring unit when the mechanical impedance data of the isolator is known,using methods such as the inverse derivation method and the graphical method..