Performance Analysis And Structure Optimization Of Floating Raft System Based On Finite Element Method

The floating raft vibration isolation technology is a common method for vibration isolation and noise reduction of warship equipment.The relevant theoretical system is relatively mature,but the floating raft system designed according to different requirements has different complexity in practical applications,and how to choose structural factors such as the location of equipment and vibration isolation and the form of structure also lacks a uniform reference standard.In order to achieve a better vibration isolation effect of the floating raft system,it is necessary to analyze and calculate the designed structure while referring to the similar structural design.This paper studies some problems in the design of floating raft system.Firstly,the static analysis method is used to study the static characteristics of the cabin in the Positive float,lateral tilt and longitudinal tilt states.The displacement of the equipment structure,the stress level and the deformation of the vibration isolator are obtained.The calculation results show that the static strength of the floating raft system meets the requirements.Then the natural frequencies of the truss and floating raft isolation system are obtained by modal analysis,and it is analyzed whether the equipment will resonate with the truss during operation.The harmonic response calculation of the vibration isolation system is carried out,and the acceleration response of each part of the vibration isolation system is obtained when different frequency loads are applied to the equipment.The acceleration is converted into the vibration level,and the vibration isolation drop is used to evaluate the vibration isolation effect of the floating system when Equipment is vibrating.Noise effect.The results show that the vibration isolation performance is excellent,and in the low frequency range,the vibration isolation effect is better than the high frequency range.Then the transient analysis method is used to study the impact resistance of the floating raft system.The impact response of the floating raft vibration isolation system is calculated by the mass method,and the deformation of the vibration isolator,the acceleration response of the equipment and the structural stress change under the standard impact environment are obtained.The results show that the dynamic strength of the floating raft system meets the requirements,and the impact resistance is excellent.The peak value of the acceleration response of the equipment is generally about one-eighth of the peak value of the input acceleration.Finally,the truss structure is optimized.Under the premise of keeping the natural frequency basically,the truss quality is reduced by reducing the hole or reducing the plate thickness on the truss plate structure.the truss quality is reduced by about one-seventh after optimization,and the dynamic characteristics of the truss structure before and after optimization are basically the same.The optimization effect is obvious.