Study On Optimized Simulation And Design Of Vibration Isolation System On Board

Vibration isolation on board plays an important role in making sure of ship's safety,comfort and invisibility.Based on the model,parameters and design concept,the design of ship vibration isolation system is optimized in this thesis.In traditional vibration isolation system modeling theory,the foundation and equipment are treated as rigid bodies,which is not consistent with the actual case,hence their flexibility,in this thesis,is taken into account in the optimization of modeling so that it is closer to the actual situation.In this model,status and characteristics as well as response of vibration system with flexibility of foundation considered are discussed in detail using power flow as evaluation index.The influence of the flexibility of the equipment on the impact resistance of the system is also analyzed in this paper.Firstly,the calculation method of the traditional impact model is reviewed and its limitation is analyzed.Then,the elastic response model of the flexible beam is established.The numerical solution of the semi-analytical solution of the model under arbitrary excitation is given.The influence of the parameters such as the arrangement of the isolator,the number of the isolators and the rigidity of the equipment on the impact resistance of the system is analyzed and the column drop test is carried out to verify Reliability of theoretical analysis.Proper calculation and detection of the characteristic parameters of the components are of great significance for the design of the vibration isolation system.Static stiffness,dynamic stiffness and impact stiffness are mainly used to describe the strength of a traditional vibration isolator,but the stiffness of the vibration isolator varies with the vibration frequency in reality,that is,the stiffness is a function of the vibration frequency,and the stiffnesses under the condition of zero frequency and natural frequency correspond to static stiffness and dynamic stiffness.Based on relevant papers and the summarization of numerous experimental results,a formula for the stiffness of the rubber isolator,which varies with frequency,is proposed.At the same time,this paper presents an impedance measurement method based on acceleration measurement,replacing the traditional force and velocity sensors with more mature acceleration measurement technology,which avoids the limitation of the measurement accuracy and the narrow effective frequency bandThe above are the optimization and improvement of traditional model and theory.A new idea of the vibration isolator's structure design is put forward in this thesis.Considering that the shear wave absorption capacity of rubber material is very strong,the longitudinal wave is converted into shear waves as much as possible based on the theory of waveform conversion to increase the absorption of shear wave and vibration energy and improve vibration isolation efficiency.The test of the sample verifies the feasibility of the new concept of isolator design.