Research On Dynamic Characteristics And Vibration Isolation Mechanism Of Laminated Metal Vibration Isolator

The vibration and noise reduction of marine power machinery is always an important consideration in the design of the ship. Marine gear box as an important part of marine power machinery, and it is an important research direction for its vibration energy transfer, especially for the suppression of high frequency resonance energy transfer. The laminated metal vibration isolator which is studied in this paper is a new type of vibration isolation device,which is mainly used for the vibration isolation of marine gear box, and it has theoretical and practical significance to improve the design quality of marine gear box by researching its dynamic characteristics and vibration isolation mechanism. It also provides references for the design and application of the same type of vibration isolation structure.In this paper, the vibration isolation structure of vibration isolator is the focus of the research, and the key technology of the vibration isolation mechanism of laminated metal vibration isolator is studied. It mainly solves the key technical problems, such as the suppression of high frequency resonance energy transfer by laminated metal vibration isolator,the contact friction characteristics and vibration characteristics of interlamination. The main achievements involve the following aspects:1. Based on the surface fractal theory, the numerical simulation of the micro surface topography of the vibration isolation sheet is carried out. The finite element simulation of the contact characteristics of the vibration isolation sheets is made by contact mechanics theory,and the energy dissipation mechanism of the vibration isolator under the action of static load is explored.2. The surface contact model of laminated vibration isolation structure is established. The finite element method is used to simulate the effects of different contact surfaces and different friction coefficients on the energy dissipation capacity of dry friction. The simulate result shows that the increase of the layer number and the friction coefficient of the contact surface will increase the amount of dry friction energy dissipation. However, this kind of dissipation ability has the characteristic of marginal decline.3. Based on the analysis of the vibration isolation mechanism, the double layer and multilayer stack model are established. The natural frequency and corresponding modes of stacked structure models are analyzed through modal simulation, the response characteristics of the models are analyzed by sweeping the frequency interval, the transfer characteristics of the vibration in the layer structure is researched through the finite element simulation. In the observation of the contact stress change of the slave contact surface, the contact stress regression mechanism of the laminated metal vibration isolation structure on the high frequency resonance is found. An explanatory conjecture for the reason of this mechanism was tentatively proposed: The resonance leads to contact pressure of actual contact area of metal surface to soar, and so that the plastic flow of the actual contact area which leads to the dissipation of energy is made.4. The static characteristics and vibration characteristics of the laminated structure model are researched by experiments, the hysteretic characteristics of different laminated structures under the same displacement are analyzed by static experiments, the hysteretic curves of the vibration isolator with different displacement are drawn; the effects of different layers on the vibration response of laminated composite structures were analyzed by the sine sweep frequency and random vibration test.