Research On Parameter Adjustment Mechanism Of Ship Equipment Vibration Test Bench

With the rapid development of China’s economy and the continuous improvement of comprehensive national strength,the demand for various ships increases.At the same time,warships,luxury cruise ships and other high-tech ships have also been greatly developed,which puts forward higher requirements for the technology of vibration reduction and noise reduction of ships.Floating raft vibration isolation system is the most widely used ship vibration isolation technology at present.In the evaluation and prediction of the floating raft vibration isolation system,the vibration response data of the installation equipment should be known,but the support of the measured vibration response data is very different from the actual support of the vibration isolation system,which has a great impact on the calculation results of the vibration isolation effect.Therefore,this paper hopes to study a semi-active vibration test bench with adjustable support,which can provide a support condition close to the actual installation environment during equipment vibration test.In this paper,the finite element software ANSYS is used to simulate the vibration.Firstly,the reliability of vibration simulation using finite element method is verified by compared with a reference.Then,a centrifugal pump is selected as a ship equipment,and a brief three-dimensional model and finite element model of the centrifugal pump are established.The harmonic response analysis of ANSYS is used to simulate the vibration under different support conditions(stiffness and damping).The results show that the support stiffness has great influence on the vibration response of the equipment,while the damping has little influence;In the prediction and evaluation of vibration isolation effect of mechanical equipment,the influence of support stiffness on the vibration response of equipment must be considered,otherwise it will have a great impact on the calculation of vibration isolation effect.Then,based on a fixed middle simply supported beam with cantilever,a mechanical structure variable stiffness isolator is designed,its three-dimensional model and finite element model are established,and the variable stiffness performance is calculated by ANSYS.The results show that: when the position of the movable simple support moves in the range of 0.01 m to 0.19 m,the vibration isolator has accurate variable stiffness adjustment performance.A spring passive vibration isolator is designed and its model is established.Finally,based on the vibration isolator,a vibration test-bed with adjustable stiffness is designed,and its three-dimensional model and finite element model are established.Through the combination of three variable stiffness isolators,the test-bed can carry out accurate continuous stiffness adjustment within a certain stiffness range.A simplified test bench model was established as a contrast model by using the spring damping unit to simulate the vibration isolator,which is a common method in the study of vibration isolation system.The harmonic response of the test bench model and the contrast model are analyzed respectively.The vibration test effect of the test bench with different support stiffness is studied through eight groups of examples.The vibration test effect of different adjustment methods with the same stiffness is studied through two groups of examples.The vibration response error of the moving simple support is analyzed when it is not moving accurately.The results show that: the test-bed designed in this paper has a good stiffness adjustment effect,for different stiffness,the vibration test error in most frequency bands is very small,and has a good variable stiffness vibration test performance.